{"product_id":"stainless-steel-m3-thumb-screws-high-head-knurled-screw-bolts-18-25-30mm","title":"Stainless Steel M3 Thumb Screws High head Knurled Screw Bolts 18\/25\/30mm","description":"\u003cdiv class=\"hdiy-desc\"\u003e\n\n\u003cdiv class=\"hdiy-overview\"\u003e\n\u003ch2\u003eM3 Stainless Steel Thumb Screws — Tool-Free Fastening for Precision Applications\u003c\/h2\u003e\n\u003cp\u003eWhen you need to repeatedly remove and reattach panels, covers, or components without reaching for a screwdriver, standard hex bolts become a daily frustration. Engineers, makers, and equipment technicians who work with enclosures, jigs, or instrument housings need a fastener they can tighten and release by hand — reliably, every time. These M3 stainless steel thumb screws with a knurled high head are built for exactly that workflow.\u003c\/p\u003e\n\u003cp\u003eEach thumb screw features an M3 metric thread with a 0.5mm pitch and a knurled cylindrical high head for a secure finger grip. The fastener body is machined from 304 stainless steel, offering solid corrosion resistance in both indoor and light outdoor environments. Available in three shaft lengths — 18mm (~0.71 in), 25mm (~0.98 in), and 30mm (~1.18 in) — to suit a range of panel thicknesses and clearance depths.\u003c\/p\u003e\n\u003cp\u003eTypical use cases include securing 3D printer access panels and electronics enclosures, fastening instrument rack covers in audio and lab equipment, assembling jigs and fixtures in light manufacturing, and attaching removable guards or shields in workshop machinery. The knurled grip pattern makes these M3 thumb screws particularly well-suited for frequent hand-adjustment cycles where tool access is limited or inconvenient.\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cdiv class=\"hdiy-compat\"\u003e\n\u003cspan class=\"hdiy-compat-icon\"\u003e🔩\u003c\/span\u003e\n\u003cstrong\u003eCompatibility:\u003c\/strong\u003e M3 metric thread (pitch 0.5mm). Fits standard M3 threaded holes and inserts. Verify clearance depth against your chosen shaft length (18 \/ 25 \/ 30mm) before ordering.\n\u003c\/div\u003e\n\n\u003cdiv class=\"hdiy-features\"\u003e\n\u003ch2\u003e✅ Key Features of These M3 Stainless Steel Thumb Screws\u003c\/h2\u003e\n\u003cul class=\"hdiy-list\"\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🖐️\u003c\/span\u003e \u003cstrong\u003eKnurled High Head for Positive Grip\u003c\/strong\u003e — The raised cylindrical head with a knurled outer surface gives your fingers enough purchase to apply consistent torque without slipping, even with slightly damp or gloved hands.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🦾\u003c\/span\u003e \u003cstrong\u003e304 Stainless Steel Construction\u003c\/strong\u003e — Resists rust and surface oxidation in humid, indoor, and light outdoor environments. Maintains dimensional accuracy over repeated use cycles without galling or thread wear.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e📏\u003c\/span\u003e \u003cstrong\u003eThree Shaft Lengths Available\u003c\/strong\u003e — Choose 18mm, 25mm, or 30mm to match your panel stack-up. All three share the same M3 × 0.5mm thread spec, so you can mix lengths across the same assembly.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🔄\u003c\/span\u003e \u003cstrong\u003eTool-Free Installation and Removal\u003c\/strong\u003e — Designed for hand-tightening in applications where a screwdriver or hex key is impractical. Reduces assembly time on enclosures, covers, and access panels that are opened frequently.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e📦\u003c\/span\u003e \u003cstrong\u003eFlexible Quantity Options\u003c\/strong\u003e — Available in packs of 1, 5, 20, 50, or 100 pieces. Order a single unit for a prototype or a bulk pack for production runs and spares inventory.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e⚙️\u003c\/span\u003e \u003cstrong\u003eConsistent Thread Tolerance\u003c\/strong\u003e — Machined to standard M3 metric tolerances, ensuring smooth engagement with tapped holes and threaded inserts without cross-threading or binding.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\n\u003cdiv class=\"hdiy-table-wrap\"\u003e\n\u003ch2\u003e📐 Technical Specifications — M3 Thumb Screws\u003c\/h2\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eThread Size\u003c\/th\u003e\n\u003ctd\u003eM3\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eThread Pitch\u003c\/th\u003e\n\u003ctd\u003e0.5mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eShaft Length Options\u003c\/th\u003e\n\u003ctd\u003e18mm \/ 25mm \/ 30mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eHead Style\u003c\/th\u003e\n\u003ctd\u003eHigh Knurled Cylindrical Head\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eDrive Style\u003c\/th\u003e\n\u003ctd\u003eThumb (hand-tightened, no tool required)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eMaterial\u003c\/th\u003e\n\u003ctd\u003e304 Stainless Steel\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eFinish\u003c\/th\u003e\n\u003ctd\u003eNatural (brushed stainless)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eThread Standard\u003c\/th\u003e\n\u003ctd\u003eISO Metric\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eQuantity per Pack\u003c\/th\u003e\n\u003ctd\u003e1 \/ 5 \/ 20 \/ 50 \/ 100 pcs (see variant options)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight per Piece\u003c\/th\u003e\n\u003ctd\u003eSee variant options\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\n\u003cdiv class=\"hdiy-faq\"\u003e\n\u003ch2\u003e❓ Frequently Asked Questions\u003c\/h2\u003e\n\n\u003cdetails\u003e\n\u003csummary\u003eWhat shaft length should I choose — 18mm, 25mm, or 30mm?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eMeasure the total depth from the top of your panel surface to the bottom of the threaded hole or insert, then subtract 1–2mm for clearance. If your panel is thin (typically under 3mm) and the threaded hole is shallow, 18mm is usually sufficient. For thicker panels or deeper inserts, 25mm or 30mm gives you more thread engagement and a more secure hold. When in doubt, 25mm is the most versatile choice for general enclosure work.\u003c\/p\u003e\u003c\/div\u003e\n\u003c\/details\u003e\n\n\u003cdetails\u003e\n\u003csummary\u003eHow strong are these thumb screws compared to standard hex bolts?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eThumb screws are designed for hand-tightening, so the clamping force is lower than a torqued hex bolt. They are well-suited for securing access panels, covers, and non-structural components that need to be removed regularly. For structural joints or high-vibration environments where a specific torque value is required, a standard hex or socket head cap screw is the better choice.\u003c\/p\u003e\u003c\/div\u003e\n\u003c\/details\u003e\n\n\u003cdetails\u003e\n\u003csummary\u003eAre these screws corrosion-resistant enough for outdoor or humid environments?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003e304 stainless steel provides good resistance to rust and surface oxidation in most indoor and light outdoor conditions, including humid workshops, light rain exposure, and marine-adjacent environments. For continuous saltwater immersion or highly aggressive chemical environments, 316 stainless steel would be a more appropriate specification. Contact us to confirm suitability for your specific application.\u003c\/p\u003e\u003c\/div\u003e\n\u003c\/details\u003e\n\n\u003cdetails\u003e\n\u003csummary\u003eWill these fit standard M3 threaded inserts and tapped holes?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eYes. These screws use the standard ISO metric M3 × 0.5mm thread profile, which is compatible with any M3 tapped hole or threaded insert machined to that standard — including brass heat-set inserts commonly used in 3D-printed parts, standard steel tapped holes, and M3 hex standoffs. Always verify the insert or hole thread pitch is 0.5mm before ordering.\u003c\/p\u003e\u003c\/div\u003e\n\u003c\/details\u003e\n\n\u003cdetails\u003e\n\u003csummary\u003eHow do I decide between ordering 5, 20, 50, or 100 pieces?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eFor a single prototype or repair, the 1-piece or 5-piece option keeps cost low. If you are building a small batch of enclosures (typically 3–10 units) with 4–6 screws each, the 20-piece pack is usually the most cost-effective. The 50- and 100-piece packs are best for production runs, stocking a workshop spares bin, or projects where you anticipate ongoing demand for the same size.\u003c\/p\u003e\u003c\/div\u003e\n\u003c\/details\u003e\n\n\u003cdetails\u003e\n\u003csummary\u003eCan I use these in a 3D-printed enclosure with heat-set M3 inserts?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eYes, this is one of the most common use cases. Heat-set M3 brass inserts installed in PLA, PETG, or ABS panels accept standard M3 × 0.5mm threads. The knurled thumb head makes it easy to hand-tighten without over-torquing the insert, which is a common cause of insert pull-out in printed parts. The 18mm length works well for most standard panel thicknesses of 3–5mm with a typical insert depth of 4–6mm.\u003c\/p\u003e\u003c\/div\u003e\n\u003c\/details\u003e\n\n\u003cdetails\u003e\n\u003csummary\u003eDo the three size variants (18mm, 25mm, 30mm) share the same head dimensions?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eYes. All three shaft length variants use the same M3 knurled high head, so the grip feel and head diameter are consistent across sizes. This means you can use different lengths in the same assembly without any visual mismatch at the head level — useful when panel thickness varies across different sections of the same enclosure.\u003c\/p\u003e\u003c\/div\u003e\n\u003c\/details\u003e\n\n\u003c\/div\u003e\n\n\u003cdiv class=\"hdiy-cta\"\u003e\n🛒 Select your Size (D*L) and quantity above, then add to cart.\n\u003c\/div\u003e\n\n\u003c\/div\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"FAQPage\",\n  \"mainEntity\": [\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What shaft length should I choose — 18mm, 25mm, or 30mm?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Measure the total depth from the top of your panel surface to the bottom of the threaded hole or insert, then subtract 1–2mm for clearance. If your panel is thin (typically under 3mm) and the threaded hole is shallow, 18mm is usually sufficient. For thicker panels or deeper inserts, 25mm or 30mm gives you more thread engagement. When in doubt, 25mm is the most versatile choice for general enclosure work.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"How strong are these thumb screws compared to standard hex bolts?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Thumb screws are designed for hand-tightening, so the clamping force is lower than a torqued hex bolt. They are well-suited for securing access panels, covers, and non-structural components that need to be removed regularly.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Are these screws corrosion-resistant enough for outdoor or humid environments?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"304 stainless steel provides good resistance to rust and surface oxidation in most indoor and light outdoor conditions. For continuous saltwater immersion or highly aggressive chemical environments, 316 stainless steel would be more appropriate.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Will these fit standard M3 threaded inserts and tapped holes?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes. These screws use the standard ISO metric M3 × 0.5mm thread profile, compatible with any M3 tapped hole or threaded insert machined to that standard, including brass heat-set inserts used in 3D-printed parts.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"How do I decide between ordering 5, 20, 50, or 100 pieces?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"For a single prototype or repair, the 1 or 5-piece option keeps cost low. For small batch builds, the 20-piece pack is usually most cost-effective. The 50- and 100-piece packs are best for production runs or stocking a workshop spares bin.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Can I use these in a 3D-printed enclosure with heat-set M3 inserts?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes. Heat-set M3 brass inserts in PLA, PETG, or ABS panels accept standard M3 × 0.5mm threads. The knurled thumb head makes it easy to hand-tighten without over-torquing the insert. The 18mm length works well for most panel thicknesses of 3–5mm.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Do the three size variants share the same head dimensions?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes. All three shaft length variants use the same M3 knurled high head, so grip feel and head diameter are consistent across sizes. You can use different lengths in the same assembly without visual mismatch at the head level.\"\n      }\n    }\n  ]\n}\n\u003c\/script\u003e","brand":"HomeDIYer","offers":[{"title":"M3*18mm \/ 1","offer_id":52291511582994,"sku":"AWM2227x1","price":2.16,"currency_code":"USD","in_stock":true},{"title":"M3*18mm \/ 5","offer_id":52291511615762,"sku":"AWM2227x5","price":4.08,"currency_code":"USD","in_stock":true},{"title":"M3*18mm \/ 20","offer_id":52291511648530,"sku":"AWM2227x20","price":13.6,"currency_code":"USD","in_stock":true},{"title":"M3*18mm \/ 50","offer_id":52291511681298,"sku":"AWM2227x50","price":34.0,"currency_code":"USD","in_stock":true},{"title":"M3*18mm \/ 100","offer_id":52291511714066,"sku":"AWM2227x100","price":50.17,"currency_code":"USD","in_stock":true},{"title":"M3*30mm \/ 1","offer_id":52291511746834,"sku":"AWM2228x1","price":2.3,"currency_code":"USD","in_stock":true},{"title":"M3*30mm \/ 5","offer_id":52291511779602,"sku":"AWM2228x5","price":4.34,"currency_code":"USD","in_stock":true},{"title":"M3*30mm \/ 20","offer_id":52291511812370,"sku":"AWM2228x20","price":14.81,"currency_code":"USD","in_stock":true},{"title":"M3*30mm \/ 50","offer_id":52291511845138,"sku":"AWM2228x50","price":35.7,"currency_code":"USD","in_stock":true},{"title":"M3*30mm \/ 100","offer_id":52291511877906,"sku":"AWM2228x100","price":70.52,"currency_code":"USD","in_stock":true},{"title":"M3*25mm \/ 1","offer_id":52291511910674,"sku":"AWM2229x1","price":2.31,"currency_code":"USD","in_stock":true},{"title":"M3*25mm \/ 5","offer_id":52291511943442,"sku":"AWM2229x5","price":4.47,"currency_code":"USD","in_stock":true},{"title":"M3*25mm \/ 20","offer_id":52291511976210,"sku":"AWM2229x20","price":14.69,"currency_code":"USD","in_stock":true},{"title":"M3*25mm \/ 50","offer_id":52291512008978,"sku":"AWM2229x50","price":35.48,"currency_code":"USD","in_stock":true},{"title":"M3*25mm \/ 100","offer_id":52291512041746,"sku":"AWM2229x100","price":70.72,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0884\/8936\/1682\/files\/Picture1of4_fc2502e0-b0b3-4b87-9948-8a6030da8b29.jpg?v=1781883176","url":"https:\/\/homediyer.com\/products\/stainless-steel-m3-thumb-screws-high-head-knurled-screw-bolts-18-25-30mm","provider":"HomeDIYer","version":"1.0","type":"link"}