{"id":13852,"date":"2026-07-30T06:48:23","date_gmt":"2026-07-30T06:48:23","guid":{"rendered":"https:\/\/hlh-js.com\/?p=13852"},"modified":"2026-07-30T06:48:23","modified_gmt":"2026-07-30T06:48:23","slug":"ceramic-bead-size-selection-for-sls-powder-removal-matching-mesh-to-part-geometry","status":"publish","type":"post","link":"https:\/\/hlh-js.com\/es\/resource\/blog\/ceramic-bead-size-selection-for-sls-powder-removal-matching-mesh-to-part-geometry\/","title":{"rendered":"Ceramic Bead Size Selection for SLS Powder Removal: Matching Mesh to Part Geometry"},"content":{"rendered":"<script type=\"application\/ld+json\">{\n    \"@context\": \"https:\\\/\\\/schema.org\",\n    \"@graph\": [\n        {\n            \"@type\": \"Article\",\n            \"headline\": \"Ceramic Bead Size Selection for SLS Powder Removal: Matching Mesh to Part Geometry\",\n            \"description\": \"Complete ceramic bead size selection guide for SLS depowdering \\u2014 mesh-to-mm conversion, Ra and cycle time trade-offs, internal channel sizing rules, and a full selection matrix across PA12, PA11, and TPU SLS materials and geometry types.\",\n            \"datePublished\": \"2026-07-27\",\n            \"dateModified\": \"2026-07-27\",\n            \"author\": {\n                \"@type\": \"Organization\",\n                \"name\": \"Jiangsu Henglihong Technology Co., Ltd.\",\n                \"url\": \"https:\\\/\\\/hlh-js.com\"\n            },\n            \"publisher\": {\n                \"@type\": \"Organization\",\n                \"name\": \"Jiangsu Henglihong Technology Co., Ltd.\",\n                \"url\": \"https:\\\/\\\/hlh-js.com\"\n            },\n            \"mainEntityOfPage\": {\n                \"@type\": \"WebPage\",\n                \"@id\": \"https:\\\/\\\/hlh-js.com\\\/resource\\\/blog\\\/ceramic-bead-size-selection-for-sls-powder-removal-matching-mesh-to-part-geometry\\\/\"\n            }\n        },\n        {\n            \"@type\": \"FAQPage\",\n            \"mainEntity\": [\n                {\n                    \"@type\": \"Question\",\n                    \"name\": \"What is the most commonly used ceramic bead size for PA12 SLS depowdering?\",\n                    \"acceptedAnswer\": {\n                        \"@type\": \"Answer\",\n                        \"text\": \"The 0.15 to 0.25 mm size range (approximately 60\\u2013100 mesh) is the most widely used for standard PA12 SLS production with moderate geometric complexity. It delivers Ra 6\\u201311 \\u00b5m at standard blast pressures of 55\\u201370 PSI, with cycle times of 5\\u201310 minutes for medium-complexity parts. This range balances cleaning effectiveness, surface finish quality, and cycle time efficiency \\u2014 making it the default starting point for most PA12 operations.\"\n                    }\n                },\n                {\n                    \"@type\": \"Question\",\n                    \"name\": \"How do I calculate the maximum bead size for an internal SLS channel?\",\n                    \"acceptedAnswer\": {\n                        \"@type\": \"Answer\",\n                        \"text\": \"Apply the one-quarter rule: the maximum safe bead diameter equals one-quarter of the smallest internal channel dimension that needs cleaning. For a 2 mm channel, use beads \\u2264 0.5 mm; for a 1 mm channel, \\u2264 0.25 mm; for a 0.6 mm channel, \\u2264 0.15 mm; for a 0.4 mm channel, \\u2264 0.10 mm. Beads above this threshold bridge the channel entrance and never enter, leaving interior surfaces unblasted.\"\n                    }\n                },\n                {\n                    \"@type\": \"Question\",\n                    \"name\": \"If I use finer beads to improve surface finish, how much longer will the cycle take?\",\n                    \"acceptedAnswer\": {\n                        \"@type\": \"Answer\",\n                        \"text\": \"Reducing bead size by one class (for example, from 0.15\\u20130.25 mm to 0.10\\u20130.15 mm) typically increases cycle time by 30 to 60% to achieve equivalent cleaning coverage, because the smaller beads deliver less energy per impact and cover less area per pass. The exact cycle time increase depends on part geometry and the blast pressure used. For operations where surface finish Ra is the primary driver, the longer cycle at finer bead size is worth the throughput trade-off. For operations where throughput is the priority and Ra 7\\u201311 \\u00b5m is acceptable, stay with the 0.15\\u20130.25 mm range.\"\n                    }\n                },\n                {\n                    \"@type\": \"Question\",\n                    \"name\": \"Should I blend two bead sizes for a build containing both complex and simple geometry parts?\",\n                    \"acceptedAnswer\": {\n                        \"@type\": \"Answer\",\n                        \"text\": \"Blending two size fractions is generally not recommended for SLS depowdering. A mixed charge produces a Ra value between the two grades, which may not satisfy either requirement adequately, and fine beads in the mix may bridge fine channels while coarse beads prevent penetration. The better approach is to set the bead size for the finest feature in the build that requires cleaning, and accept the longer cycle time this imposes on simpler geometry parts in the same batch. If throughput is critical, run separate blast cycles for complex-geometry and simple-geometry parts.\"\n                    }\n                }\n            ]\n        }\n    ]\n}<\/script>\n<style>\n.hlh-sls-c04{font-family:'Segoe UI',Arial,sans-serif;color:#2c3e50;line-height:1.82;max-width:860px;margin:0 auto;font-size:16px}\n.hlh-sls-c04 h1{font-size:2rem;color:#1a3456;font-weight:700;line-height:1.28;margin:0 0 .5rem}\n.hlh-sls-c04 h2{font-size:1.46rem;color:#1a3456;font-weight:700;margin:2.5rem 0 .72rem;padding-bottom:.4rem;border-bottom:3px solid #d86e18}\n.hlh-sls-c04 h3{font-size:1.14rem;color:#1a3456;font-weight:700;margin:1.75rem 0 .5rem}\n.hlh-sls-c04 h4{font-size:1rem;color:#d86e18;font-weight:700;margin:1.2rem 0 .35rem}\n.hlh-sls-c04 p{margin:0 0 1rem}.hlh-sls-c04 ul,.hlh-sls-c04 ol{margin:0 0 1rem 1.5rem;padding:0}.hlh-sls-c04 li{margin-bottom:.38rem}\n.hlh-sls-c04 a{color:#d86e18;text-decoration:none;border-bottom:1px solid rgba(216,110,24,.35);transition:color 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.fq{background:#f0f4f8;padding:.9rem 1.2rem;font-weight:600;font-size:.94rem;color:#1a3456;cursor:pointer;display:flex;justify-content:space-between;align-items:center;border:none;width:100%;text-align:left;transition:background .18s}.hlh-sls-c04 .fq:hover{background:#e4edf6}\n.hlh-sls-c04 .fi-icon{font-size:1.2rem;color:#d86e18;flex-shrink:0;margin-left:.9rem;transition:transform .22s;font-weight:400}.hlh-sls-c04 .fq.open .fi-icon{transform:rotate(45deg)}\n.hlh-sls-c04 .fa{display:none;padding:.88rem 1.2rem 1rem;font-size:.92rem;background:#fff;color:#2c3e50;line-height:1.78;border-top:1px solid #e2eaf2}.hlh-sls-c04 .fa.open{display:block}.hlh-sls-c04 .fa p:last-child{margin-bottom:0}\n.hlh-sls-c04 .cta{background:linear-gradient(135deg,#1a3456 0%,#24466e 100%);border-radius:10px;padding:2rem 2.3rem;margin:2.8rem 0 1rem;text-align:center}\n.hlh-sls-c04 .cta h3{color:#fff;font-size:1.28rem;margin:0 0 .6rem}.hlh-sls-c04 .cta p{color:rgba(255,255,255,.84);font-size:.94rem;margin-bottom:1.3rem}\n.hlh-sls-c04 .btn{display:inline-block;background:#d86e18;color:#fff!important;font-weight:700;font-size:1rem;padding:.73rem 2.1rem;border-radius:4px;text-decoration:none!important;border:none!important;transition:background .2s}.hlh-sls-c04 .btn:hover{background:#b85a10}\n@media(max-width:640px){.hlh-sls-c04 h1{font-size:1.5rem}.hlh-sls-c04 h2{font-size:1.2rem}.hlh-sls-c04 .cta{padding:1.5rem 1.2rem}.hlh-sls-c04 .dive{flex-direction:column;gap:.4rem}}\n<\/style>\n<article class=\"hlh-sls-c04\">\n<div class=\"back\">&#8592; Part of: <a href=\"https:\/\/hlh-js.com\/resource\/blog\/ceramic-beads-sls-powder-removal-complete-guide\/\" target=\"_blank\" rel=\"noopener noreferrer\">Ceramic Beads for SLS Powder Removal \u2014 Complete Guide<\/a><\/div>\n<h1>Ceramic Bead Size Selection for SLS Powder Removal: Matching Mesh to Part Geometry<\/h1>\n<p class=\"meta\">By Jiangsu Henglihong Technology Co., Ltd. &nbsp;|&nbsp; Last updated: July 2026<\/p>\n<p class=\"lead\">Bead size is the primary variable in ceramic bead SLS depowdering \u2014 more influential than blast pressure on both surface finish Ra and the ability to clean internal channels. Choose too coarse and fine features stay powder-filled; choose too fine and cycle times become impractical. This reference guide provides the complete size selection framework: mesh-to-mm conversion, Ra and cycle time trade-offs, the internal channel sizing rule, and a full selection matrix across all SLS materials and geometry categories.<\/p>\n<div class=\"stats\">\n  <div class=\"stat\"><span class=\"stat-n\">0.05\u20130.35 mm<\/span><span class=\"stat-l\">Practical bead size range for SLS depowdering<\/span><\/div>\n  <div class=\"stat\"><span class=\"stat-n\">1\/4 rule<\/span><span class=\"stat-l\">Bead dia. \u2264 1\/4 of smallest internal channel<\/span><\/div>\n  <div class=\"stat\"><span class=\"stat-n\">Ra 3\u201316 \u00b5m<\/span><span class=\"stat-l\">Achievable range across bead size grades<\/span><\/div>\n  <div class=\"stat\"><span class=\"stat-n\">1.8\u20132.5\u00d7<\/span><span class=\"stat-l\">Typical cycle time increase from 0.20 mm to 0.08 mm<\/span><\/div>\n<\/div>\n<nav class=\"toc\"><p class=\"toc-h\">Table of Contents<\/p>\n<ol>\n<li><a href=\"#c04-why\">Why Bead Size Is the Primary Variable<\/a><\/li>\n<li><a href=\"#c04-spec\">Reading Ceramic Bead Size Specifications<\/a><\/li>\n<li><a href=\"#c04-tradeoff\">Ra and Cycle Time Trade-offs by Bead Size<\/a><\/li>\n<li><a href=\"#c04-matrix\">Complete Bead Size Selection Matrix<\/a><\/li>\n<li><a href=\"#c04-channel\">The Internal Channel Sizing Rule<\/a><\/li>\n<li><a href=\"#c04-multi\">Multi-Geometry Build Strategy<\/a><\/li>\n<li><a href=\"#c04-dye\">Bead Size Selection for Pre-Dyeing Blast<\/a><\/li>\n<li><a href=\"#c04-faq\">Preguntas frecuentes<\/a><\/li>\n<\/ol><\/nav>\n\n<h2 id=\"c04-why\">1. Why Bead Size Is the Primary Variable<\/h2>\n<p>In ceramic bead SLS depowdering, three parameters control the cleaning outcome: bead size, blast pressure, and blast time. Of these, bead size has the broadest influence \u2014 it determines both the ceiling on surface finish Ra and the physical access to internal features. Blast pressure adjusts the energy within the range set by bead size; time adjusts coverage completeness. But no amount of pressure increase or extended cycle time can compensate for a bead that is too large to enter a channel that needs cleaning. Bead size must be specified first.<\/p>\n<p>The physics are straightforward. A bead&#8217;s kinetic energy is proportional to its mass (which scales with diameter cubed) and the square of its velocity. Doubling bead diameter from 0.10 mm to 0.20 mm increases mass \u2014 and therefore kinetic energy \u2014 by approximately 8\u00d7, at the same velocity. This energy increase delivers faster cleaning but creates a coarser peening action on the surface, producing higher Ra. The trade-off is inherent to the physics and cannot be fully compensated by reducing pressure: using coarser beads at lower pressure gives less energy than fine beads at that same lower pressure, with the additional downside of reduced channel access.<\/p>\n\n<h2 id=\"c04-spec\">2. Reading Ceramic Bead Size Specifications<\/h2>\n<p>Ceramic beads are specified in multiple systems. Understanding the equivalences prevents ordering errors and ensures you match supplier specifications to your process requirements.<\/p>\n<div class=\"tw\"><table><thead><tr><th>Size Range (mm)<\/th><th>US Mesh Range<\/th><th>Tyler Mesh Range<\/th><th>Median d\u2085\u2080 (\u00b5m)<\/th><th>Common Application Label<\/th><\/tr><\/thead>\n<tbody>\n<tr><td>0.05\u20130.10<\/td><td>150\u2013270<\/td><td>150\u2013270<\/td><td>~70<\/td><td>Ultra-fine \/ Extra-fine<\/td><\/tr>\n<tr><td>0.10\u20130.15<\/td><td>100\u2013150<\/td><td>100\u2013150<\/td><td>~125<\/td><td>Fine<\/td><\/tr>\n<tr><td>0.15\u20130.25<\/td><td>60\u2013100<\/td><td>60\u2013100<\/td><td>~200<\/td><td>Medium-fine (standard)<\/td><\/tr>\n<tr><td>0.25-0.35<\/td><td>45\u201360<\/td><td>48\u201360<\/td><td>~300<\/td><td>Medium<\/td><\/tr>\n<tr><td>0.35\u20130.50<\/td><td>35\u201345<\/td><td>35\u201348<\/td><td>~420<\/td><td>Medium-coarse<\/td><\/tr>\n<\/tbody><\/table><\/div>\n<p>Always request the particle size distribution (PSD) data \u2014 specifically d\u2081\u2080, d\u2085\u2080, and d\u2089\u2080 \u2014 rather than relying on mesh range alone. A nominal 0.10\u20130.15 mm bead specification covers a meaningful range of particle sizes; the d\u2089\u2080 tells you the upper size limit of 90% of the particles, which governs channel access behaviour. Jiangsu Henglihong Technology Co., Ltd. supplies ISO-classified ceramic beads with full PSD documentation on request.<\/p>\n\n<h2 id=\"c04-tradeoff\">3. Ra and Cycle Time Trade-offs by Bead Size<\/h2>\n<p>The relationship between bead size, achievable Ra, and cycle time follows a consistent pattern across SLS nylon materials. The data below represents ZS ceramic beads on standard PA12 SLS at 60 PSI in a suction-feed cabinet.<\/p>\n<div class=\"tw\"><table><thead><tr><th>Bead Size (mm)<\/th><th>Typical Ra Range (\u00b5m)<\/th><th>Cycle Time Factor<\/th><th>Primary Trade-off<\/th><\/tr><\/thead>\n<tbody>\n<tr><td><strong>0.05\u20130.10<\/strong><\/td><td>Ra 3\u20136<\/td><td>2.5\u00d7 baseline<\/td><td>Finest finish; longest cycle; limited throughput<\/td><\/tr>\n<tr><td><strong>0.10\u20130.15<\/strong><\/td><td>Ra 4\u20138<\/td><td>1.6\u00d7 baseline<\/td><td>Fine finish; moderate cycle extension; good for appearance parts<\/td><\/tr>\n<tr><td><strong>0.15\u20130.25<\/strong><\/td><td>Ra 6\u201311<\/td><td>1\u00d7 (baseline)<\/td><td>Standard production range; best throughput per Ra unit<\/td><\/tr>\n<tr><td><strong>0.25-0.35<\/strong><\/td><td>Ra 9\u201316<\/td><td>0.7\u00d7 baseline<\/td><td>Faster cycle; coarser finish; limited to open geometry<\/td><\/tr>\n<\/tbody><\/table><\/div>\n<p>The cycle time factor is normalised to the 0.15\u20130.25 mm range at the same blast pressure and coverage completeness standard. In practice, switching from 0.15\u20130.25 mm to 0.10\u20130.15 mm at the same pressure adds 30\u201360% to cycle time for equivalent PA12 depowdering. Switching to 0.05\u20130.10 mm adds 120\u2013150%. This time cost must be weighed against the Ra improvement needed for the specific part application.<\/p>\n\n<h2 id=\"c04-matrix\">4. Complete Bead Size Selection Matrix<\/h2>\n<p>The table below provides a starting-point bead size recommendation for each combination of SLS material and geometric category. These are starting points, not process specifications; first-article qualification on each new part design establishes the correct protocol for that geometry.<\/p>\n<div class=\"tw\"><table><thead><tr><th>SLS Material<\/th><th>Part Category<\/th><th>Min Feature \/ Wall<\/th><th>Recommended Bead Size<\/th><th>Expected Ra<\/th><th>Cycle Factor<\/th><\/tr><\/thead>\n<tbody>\n<tr><td><strong>PA12<\/strong><\/td><td>Large open \/ simple geometry<\/td><td>Wall \u2265 3 mm<\/td><td>0.20\u20130.30 mm<\/td><td>Ra 8\u201314 \u00b5m<\/td><td>0.7\u00d7<\/td><\/tr>\n<tr><td><strong>PA12<\/strong><\/td><td>Standard production<\/td><td>Wall 2\u20133 mm<\/td><td>0.15\u20130.25 mm<\/td><td>Ra 6\u201311 \u00b5m<\/td><td>1\u00d7<\/td><\/tr>\n<tr><td><strong>PA12<\/strong><\/td><td>Complex geometry<\/td><td>Wall 1.5\u20132 mm<\/td><td>0.10\u20130.20 mm<\/td><td>Ra 5\u20139 \u00b5m<\/td><td>1.4\u00d7<\/td><\/tr>\n<tr><td><strong>PA12<\/strong><\/td><td>Fine internal channels<\/td><td>Channel 0.6\u20132 mm<\/td><td>0.10\u20130.15 mm<\/td><td>Ra 4\u20138 \u00b5m<\/td><td>1.8\u00d7<\/td><\/tr>\n<tr><td><strong>PA12<\/strong><\/td><td>Ultra-fine channels \/ lattice<\/td><td>Channel &lt;0.6 mm<\/td><td>0.05\u20130.10 mm<\/td><td>Ra 3\u20136 \u00b5m<\/td><td>2.5\u00d7<\/td><\/tr>\n<tr><td><strong>PA12<\/strong><\/td><td>Pre-dye blast (standard colour)<\/td><td>\u2014<\/td><td>0.15\u20130.20 mm<\/td><td>Ra 6\u201310 \u00b5m<\/td><td>1\u00d7<\/td><\/tr>\n<tr><td><strong>PA12<\/strong><\/td><td>Pre-dye blast (light\/bright colour)<\/td><td>\u2014<\/td><td>0.10\u20130.15 mm<\/td><td>Ra 4\u20137 \u00b5m<\/td><td>1.4\u00d7<\/td><\/tr>\n<tr><td><strong>PA12-GB<\/strong><\/td><td>Standard (glass-filled)<\/td><td>Wall \u2265 2 mm<\/td><td>0.20\u20130.30 mm<\/td><td>Ra 10\u201318 \u00b5m<\/td><td>1.2\u00d7<\/td><\/tr>\n<tr><td><strong>PA11<\/strong><\/td><td>Standard geometry<\/td><td>Wall \u2265 2 mm<\/td><td>0.15\u20130.25 mm<\/td><td>Ra 6\u201312 \u00b5m<\/td><td>1\u00d7<\/td><\/tr>\n<tr><td><strong>PA11<\/strong><\/td><td>Complex \/ flexible assembly<\/td><td>Wall 1\u20132 mm<\/td><td>0.10\u20130.15 mm<\/td><td>Ra 5\u201310 \u00b5m<\/td><td>1.5\u00d7<\/td><\/tr>\n<tr><td><strong>TPU A85\u201395<\/strong><\/td><td>Standard body geometry<\/td><td>Wall \u2265 2 mm<\/td><td>0.08\u20130.15 mm<\/td><td>Ra 10\u201316 \u00b5m<\/td><td>1.5\u00d7<\/td><\/tr>\n<tr><td><strong>TPU A85\u201395<\/strong><\/td><td>Lattice \/ fine wall<\/td><td>Strut \u2265 1.5 mm<\/td><td>0.05\u20130.10 mm<\/td><td>Ra 12\u201320 \u00b5m<\/td><td>2.0\u00d7<\/td><\/tr>\n<tr><td><strong>TPU A75\u201385<\/strong><\/td><td>Any<\/td><td>Any \u2265 1.2 mm<\/td><td>0.05\u20130.10 mm<\/td><td>Ra 12\u201322 \u00b5m<\/td><td>2.2\u00d7<\/td><\/tr>\n<\/tbody><\/table><\/div>\n\n<h2 id=\"c04-channel\">5. The Internal Channel Sizing Rule<\/h2>\n<p>Internal channels \u2014 fluid passages, wire routing tunnels, articulation slots, venting channels \u2014 are among the most common depowdering failure points in SLS production. The powder-cake removal phase and compressed-air blow-off do not clean them; ceramic bead blasting is the only reliable method. But only if the beads can physically enter.<\/p>\n<div class=\"box box-a\">\n<h4>The One-Quarter Diameter Rule<\/h4>\n<p>Maximum safe bead diameter = smallest internal channel diameter \u00f7 4<\/p>\n<ul>\n<li>4 mm channel \u2192 beads \u2264 1.0 mm (any standard size)<\/li>\n<li>2 mm channel \u2192 beads \u2264 0.50 mm (0.25\u20130.35 mm range works comfortably)<\/li>\n<li>1.5 mm channel \u2192 beads \u2264 0.375 mm (use 0.25\u20130.35 mm)<\/li>\n<li>1.0 mm channel \u2192 beads \u2264 0.25 mm (use 0.15\u20130.25 mm)<\/li>\n<li>0.6 mm channel \u2192 beads \u2264 0.15 mm (use 0.10\u20130.15 mm)<\/li>\n<li>0.4 mm channel \u2192 beads \u2264 0.10 mm (use 0.05\u20130.10 mm)<\/li>\n<\/ul>\n<\/div>\n<p>The one-quarter ratio provides the clearance margin needed for beads to enter, impact the channel wall, and exit without bridging. Beads at exactly the channel width \u2014 or larger \u2014 will bridge the entrance opening, forming a plug that prevents further entry. Bridging is particularly problematic because it is not immediately visible during blasting; the channel exit appears clean under casual inspection but the interior wall carries full semi-sintered skin.<\/p>\n<p>For blind channels \u2014 those that do not have an exit \u2014 bead blasting is inherently limited. Beads enter but cannot exit; they pack the channel. For blind channels with diameters above 4 mm, compressed-air blow-out mid-cycle can dislodge accumulated beads and allow additional cleaning passes. For blind channels below 2 mm, manual compressed-air depowdering is more practical than media blasting.<\/p>\n\n<h2 id=\"c04-multi\">6. Multi-Geometry Build Strategy<\/h2>\n<p>A common SLS production scenario: a single build contains multiple part designs, some with fine internal channels (requiring 0.10\u20130.15 mm beads) and others with simple open geometry (where 0.20\u20130.30 mm beads would suffice for faster throughput). How should bead size be selected for the batch?<\/p>\n<p><strong>Set bead size for the finest feature that requires blasting.<\/strong> In the example above, use 0.10\u20130.15 mm beads for the entire batch. The simple-geometry parts will be adequately blasted at fine bead size \u2014 the only consequence is a longer cycle time than strictly necessary for those parts. Do not compromise channel cleaning to protect throughput on simpler parts.<\/p>\n<p>The exception: if the build contains a large quantity of simple-geometry parts and only a few complex-geometry parts, it may be economical to blast the two groups in separate cycles at different bead sizes. Run the simple-geometry parts at 0.20\u20130.30 mm for fast throughput, then switch to 0.10\u20130.15 mm for the complex parts. This requires media purging between cycles if you maintain a single cabinet \u2014 approximately 2\u20135 minutes of purge time \u2014 which must be included in the throughput calculation.<\/p>\n\n<h2 id=\"c04-dye\">7. Bead Size Selection for Pre-Dyeing Blast<\/h2>\n<p>When the ceramic bead blast cycle serves as surface preparation for dyeing \u2014 as it does in the majority of PA12 and PA11 SLS colour production \u2014 the bead size selection must account for the relationship between surface Ra and dye uptake depth.<\/p>\n<p>Finer beads produce lower Ra, which means less surface micro-porosity per unit area and shallower dye penetration. Coarser beads produce higher Ra, more surface area per projected unit, and deeper colour. This relationship can be used as a direct process control variable:<\/p>\n<ul>\n<li><strong>Target: deep black, navy, or dark grey:<\/strong> use 0.15\u20130.25 mm beads (Ra 7\u201310 \u00b5m) for maximum colour depth<\/li>\n<li><strong>Target: standard commercial colours (red, blue, green):<\/strong> use 0.12\u20130.20 mm beads (Ra 6\u20139 \u00b5m) \u2014 balanced depth and colour uniformity<\/li>\n<li><strong>Target: light pastel shades or custom light tones:<\/strong> use 0.08\u20130.15 mm beads (Ra 4\u20137 \u00b5m) to limit dye uptake depth and achieve lighter saturation<\/li>\n<\/ul>\n<p>This bead size-to-colour relationship assumes constant dye bath concentration and temperature. When establishing a new colour standard, blast a reference coupon at two bead sizes (one coarser, one finer), dye both in the standard bath, and measure colour depth with a spectrophotometer to identify which size delivers the target \u0394E from the colour standard.<\/p>\n\n<div class=\"dive\"><div class=\"dive-i\">&#128196;<\/div><div>\n<span class=\"dive-l\">Related Reference<\/span>\n<a href=\"https:\/\/hlh-js.com\/resource\/blog\/color-consistency-and-dye-preparation-for-sls-parts-after-ceramic-bead-blasting\/\" target=\"_blank\" rel=\"noopener noreferrer\">Color Consistency and Dye Preparation for SLS Parts After Ceramic Bead Blasting<\/a>\n<p>Bead size to colour depth relationship data, pre-dye blast protocols by colour target, and batch colour consistency measurement methodology.<\/p>\n<\/div><\/div>\n\n<h2 id=\"c04-faq\">Preguntas frecuentes<\/h2>\n<div>\n<div class=\"fi\"><button class=\"fq\" aria-expanded=\"false\">What is the most commonly used ceramic bead size for PA12 SLS depowdering? <span class=\"fi-icon\">+<\/span><\/button>\n<div class=\"fa\"><p>The 0.15 to 0.25 mm size range (approximately 60\u2013100 mesh) is the most widely used for standard PA12 SLS production with moderate geometric complexity. It delivers Ra 6\u201311 \u00b5m at standard blast pressures of 55\u201370 PSI, with cycle times of 5\u201310 minutes for medium-complexity parts. This range balances cleaning effectiveness, surface finish quality, and cycle time efficiency \u2014 making it the default starting point for most PA12 operations and the baseline in the cycle time table in this article.<\/p><\/div><\/div>\n<div class=\"fi\"><button class=\"fq\" aria-expanded=\"false\">How do I calculate the maximum bead size for an internal SLS channel? <span class=\"fi-icon\">+<\/span><\/button>\n<div class=\"fa\"><p>Apply the one-quarter rule: the maximum safe bead diameter equals one-quarter of the smallest internal channel dimension that needs cleaning. For a 2 mm channel, use beads \u2264 0.5 mm; for a 1 mm channel, \u2264 0.25 mm; for a 0.6 mm channel, \u2264 0.15 mm; for a 0.4 mm channel, \u2264 0.10 mm. Beads above this threshold bridge the channel entrance \u2014 accumulating at the opening rather than entering and impacting the interior wall \u2014 leaving the channel interior unblasted and powder-filled despite an apparently clean exterior.<\/p><\/div><\/div>\n<div class=\"fi\"><button class=\"fq\" aria-expanded=\"false\">If I use finer beads for better surface finish, how much longer will the blast cycle take? <span class=\"fi-icon\">+<\/span><\/button>\n<div class=\"fa\"><p>Reducing bead size by one class \u2014 for example, from 0.15\u20130.25 mm to 0.10\u20130.15 mm \u2014 typically increases cycle time by 30 to 60% to achieve equivalent cleaning coverage, because smaller beads deliver less energy per impact and cover less area per pass. Moving from 0.15\u20130.25 mm all the way to 0.05\u20130.10 mm typically adds 120\u2013150% to cycle time. The exact increase depends on part geometry and blast pressure. For operations where surface finish Ra is the primary driver, the longer cycle at finer bead size is worth the throughput trade-off. For operations where throughput matters and Ra 7\u201311 \u00b5m is acceptable, stay with the 0.15\u20130.25 mm range.<\/p><\/div><\/div>\n<div class=\"fi\"><button class=\"fq\" aria-expanded=\"false\">Should I blend two bead sizes for a build with both complex and simple geometry parts? <span class=\"fi-icon\">+<\/span><\/button>\n<div class=\"fa\"><p>Blending two size fractions is generally not recommended for SLS depowdering. A mixed charge produces a Ra value between the two grades, which may not satisfy either requirement adequately. Fine beads in the mix may bridge fine channels while coarse beads are too large to enter; and the mixed charge makes Ra monitoring unreliable as the size ratio shifts over time with differential degradation rates. The better approach: set bead size for the finest feature requiring cleaning and accept the longer cycle time on simpler parts, or run separate blast cycles for complex and simple groups.<\/p><\/div><\/div>\n<\/div>\n\n<h2>Related Articles in This Series<\/h2>\n<p>Return to the <a href=\"https:\/\/hlh-js.com\/resource\/blog\/ceramic-beads-sls-powder-removal-complete-guide\/\" target=\"_blank\" rel=\"noopener noreferrer\">Ceramic Beads for SLS Powder Removal \u2014 Complete Guide<\/a> for the full overview.<\/p>\n<div class=\"rel-g\">\n<div class=\"rel-c\"><a href=\"https:\/\/hlh-js.com\/resource\/blog\/blast-pressure-and-cycle-time-for-ceramic-bead-sls-depowdering-optimization-guide\/\" target=\"_blank\" rel=\"noopener noreferrer\">Blast Pressure and Cycle Time Optimization<\/a><p>Once bead size is set, this guide optimises pressure, nozzle setup, and cycle time.<\/p><\/div>\n<div class=\"rel-c\"><a href=\"https:\/\/hlh-js.com\/resource\/blog\/surface-finish-and-ra-values-after-ceramic-bead-blasting-sls-3d-printed-parts\/\" target=\"_blank\" rel=\"noopener noreferrer\">Surface Finish Ra Values After Ceramic Bead Blasting<\/a><p>Full Ra dataset by bead grade, size, and pressure \u2014 with measurement protocol.<\/p><\/div>\n<div class=\"rel-c\"><a href=\"https:\/\/hlh-js.com\/resource\/blog\/ceramic-bead-blasting-pa12-nylon-sls-parts-depowdering-and-surface-prep\/\" target=\"_blank\" rel=\"noopener noreferrer\">PA12 SLS Depowdering Protocol<\/a><p>PA12-specific protocol applying the size selection principles in this article.<\/p><\/div>\n<div class=\"rel-c\"><a href=\"https:\/\/hlh-js.com\/resource\/blog\/ceramic-bead-blasting-tpu-flexible-sls-parts-gentle-depowdering-without-deformation\/\" target=\"_blank\" rel=\"noopener noreferrer\">Ceramic Bead Blasting for TPU Flexible SLS<\/a><p>Fine bead selection and low-pressure protocol for flexible SLS materials.<\/p><\/div>\n<div class=\"rel-c\"><a href=\"https:\/\/hlh-js.com\/resource\/blog\/color-consistency-and-dye-preparation-for-sls-parts-after-ceramic-bead-blasting\/\" target=\"_blank\" rel=\"noopener noreferrer\">Color Consistency and Dye Preparation<\/a><p>How bead size selection controls colour depth in dyed PA12\/PA11 SLS parts.<\/p><\/div>\n<div class=\"rel-c\"><a href=\"https:\/\/hlh-js.com\/resource\/blog\/wet-vs-dry-ceramic-bead-blasting-for-sls-nylon-powder-removal-process-comparison\/\" target=\"_blank\" rel=\"noopener noreferrer\">Wet vs. Dry Ceramic Bead Blasting<\/a><p>How wet blasting modifies the Ra-to-bead-size relationship for SLS nylon.<\/p><\/div>\n<\/div>\n<div class=\"cta\"><h3>Get ISO-Classified Ceramic Beads for Your SLS Bead Size Specification<\/h3>\n<p>Jiangsu Henglihong Technology Co., Ltd. supplies ZS and ZrO\u2082 ceramic blasting beads in ISO-classified size ranges from 0.05 mm to 0.60 mm with full PSD documentation. Tell us your channel dimensions and Ra target \u2014 we will specify the right size range and supply a calibrated sample for first-article qualification.<\/p>\n<a href=\"https:\/\/hlh-js.com\/contact\/\" target=\"_blank\" rel=\"noopener noreferrer\" class=\"btn\">Request Samples &amp; PSD Data<\/a><\/div>\n<\/article>\n<script>(function(){var b=document.querySelectorAll('.hlh-sls-c04 .fq');b.forEach(function(btn){btn.addEventListener('click',function(){var a=this.nextElementSibling,o=a.classList.contains('open');document.querySelectorAll('.hlh-sls-c04 .fa').forEach(function(x){x.classList.remove('open')});document.querySelectorAll('.hlh-sls-c04 .fq').forEach(function(x){x.classList.remove('open');x.setAttribute('aria-expanded','false')});if(!o){a.classList.add('open');btn.classList.add('open');btn.setAttribute('aria-expanded','true')}})})})();<\/script>","protected":false},"excerpt":{"rendered":"<p>&#8592; Part of: Ceramic Beads for SLS Powder Removal \u2014  [&#8230;]<\/p>","protected":false},"author":1,"featured_media":13854,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[62,175,138],"tags":[],"class_list":["post-13852","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog","category-industry","category-resource"],"_links":{"self":[{"href":"https:\/\/hlh-js.com\/es\/wp-json\/wp\/v2\/posts\/13852","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/hlh-js.com\/es\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/hlh-js.com\/es\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/hlh-js.com\/es\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/hlh-js.com\/es\/wp-json\/wp\/v2\/comments?post=13852"}],"version-history":[{"count":2,"href":"https:\/\/hlh-js.com\/es\/wp-json\/wp\/v2\/posts\/13852\/revisions"}],"predecessor-version":[{"id":13855,"href":"https:\/\/hlh-js.com\/es\/wp-json\/wp\/v2\/posts\/13852\/revisions\/13855"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/hlh-js.com\/es\/wp-json\/wp\/v2\/media\/13854"}],"wp:attachment":[{"href":"https:\/\/hlh-js.com\/es\/wp-json\/wp\/v2\/media?parent=13852"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/hlh-js.com\/es\/wp-json\/wp\/v2\/categories?post=13852"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/hlh-js.com\/es\/wp-json\/wp\/v2\/tags?post=13852"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}