{"product_id":"brass-knurled-thumb-screws-m3x4-5mm-flat-head","title":"Brass Knurled Thumb Screws M3×4.5mm — Flat Head Hand-Tighten Bolts for Slingshot Sight \u0026 Grip Knobs","description":"\u003cp\u003e \u003c\/p\u003e\n\u003cdiv class=\"hdiy-desc\"\u003e\n\u003cdiv class=\"hdiy-overview\"\u003e\n\u003ch2\u003eM3×4.5mm Brass Knurled Thumb Screws — Tool-Free Fastening for Slingshot Sights \u0026amp; Grip Knobs\u003c\/h2\u003e\n\u003cp\u003eAnyone who has fumbled for a screwdriver mid-adjustment on a slingshot sight or optical mount knows the frustration. These \u003cstrong\u003eM3×4.5mm brass knurled thumb screws\u003c\/strong\u003e are designed for exactly those moments — quick, tool-free tightening and loosening with a confident finger grip, whether you are in the field or at the workbench.\u003c\/p\u003e\n\u003cp\u003eEach screw features a \u003cstrong\u003eflat knurled head\u003c\/strong\u003e in solid brass, with an M3 metric thread and a 4.5mm (approximately 3\/16\") shank length. Available in natural brass finish and nickel-plated brass, sold in packs of 2, 5, 10, 20, 50, or 100 pieces to suit both single-project needs and workshop stock.\u003c\/p\u003e\n\u003cp\u003eTypical applications include \u003cstrong\u003eslingshot sight windage and elevation adjustments\u003c\/strong\u003e, hand-grip knob assemblies, instrument panel fasteners, 3D printer bed leveling screws, and any light-duty mechanism where repeated hand-tightening is needed without tools.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"hdiy-compat\"\u003e\n\u003cspan class=\"hdiy-compat-icon\"\u003e🔩\u003c\/span\u003e \u003cstrong\u003eCompatibility:\u003c\/strong\u003e M3 metric thread (standard M3×0.5mm pitch). Not compatible with imperial #4-40 or #6-32 threads. Confirm your application uses M3 metric threading before ordering.\u003c\/div\u003e\n\u003ch2\u003e✅ Key Features of These M3 Brass Knurled Thumb Screws\u003c\/h2\u003e\n\u003cul class=\"hdiy-features\"\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e✋\u003c\/span\u003e\u003cspan\u003e\u003cstrong\u003eKnurled Flat Head for Finger Control\u003c\/strong\u003e — The circumferential knurling pattern gives a secure grip for hand-tightening, making these ideal as \u003cem\u003etool-free adjustment screws\u003c\/em\u003e in slingshot sights and optical mounts.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🟡\u003c\/span\u003e\u003cspan\u003e\u003cstrong\u003eSolid Brass Construction\u003c\/strong\u003e — Brass offers inherent corrosion resistance, electrical conductivity, and a non-magnetic profile — useful in sensitive instrument and electronics enclosure applications.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🪙\u003c\/span\u003e\u003cspan\u003e\u003cstrong\u003eNickel-Plated Option Available\u003c\/strong\u003e — The Ni-plated variant adds a silver-toned finish with increased surface hardness and tarnish resistance, suitable for applications where appearance consistency matters.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e📐\u003c\/span\u003e\u003cspan\u003e\u003cstrong\u003eCompact M3×4.5mm Shank\u003c\/strong\u003e — The short 4.5mm (≈3\/16\") grip length suits shallow threaded holes common in slingshot frames, camera accessories, and lightweight DIY fixtures.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e📦\u003c\/span\u003e\u003cspan\u003e\u003cstrong\u003eFlexible Pack Quantities\u003c\/strong\u003e — Order from 2pcs up to 100pcs. Larger packs reduce per-piece cost, making them practical for \u003cem\u003ebulk thumb screw restocking\u003c\/em\u003e or multi-unit production runs.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🚚\u003c\/span\u003e\u003cspan\u003e\u003cstrong\u003eShips from US Warehouse\u003c\/strong\u003e — Stocked domestically for faster delivery across the contiguous United States, with no extended international transit times.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003e📐 Technical Specifications — M3 Flat Knurled Thumb Screws\u003c\/h2\u003e\n\u003cdiv class=\"hdiy-table-wrap\"\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eThread Standard\u003c\/th\u003e\n\u003ctd\u003eMetric M3\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eThread Pitch\u003c\/th\u003e\n\u003ctd\u003e0.5mm (standard M3 coarse pitch)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eShank Length\u003c\/th\u003e\n\u003ctd\u003e4.5mm (≈3\/16\")\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eHead Style\u003c\/th\u003e\n\u003ctd\u003eFlat knurled (circumferential knurl pattern)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eHead Diameter\u003c\/th\u003e\n\u003ctd\u003eSee variant options\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eHead Height\u003c\/th\u003e\n\u003ctd\u003eSee variant options\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eMaterial\u003c\/th\u003e\n\u003ctd\u003eBrass (CuZn alloy)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eFinish Options\u003c\/th\u003e\n\u003ctd\u003eNatural brass \/ Nickel-plated brass\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eDrive Type\u003c\/th\u003e\n\u003ctd\u003eHand-tighten (knurled head); flat-blade compatible\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003ePack Quantities\u003c\/th\u003e\n\u003ctd\u003e2 \/ 5 \/ 10 \/ 20 \/ 50 \/ 100 pcs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eApplicable Standard\u003c\/th\u003e\n\u003ctd\u003eContact us to confirm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eCountry of Origin\u003c\/th\u003e\n\u003ctd\u003eContact us to confirm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"hdiy-note\"\u003e\n\u003cspan class=\"hdiy-note-icon\"\u003e⚠️\u003c\/span\u003e \u003cstrong\u003eHeads up:\u003c\/strong\u003e Head diameter and height dimensions are not listed above. If your application has tight clearance requirements, please contact us to confirm exact head dimensions before ordering.\u003c\/div\u003e\n\u003ch2\u003e❓ Frequently Asked Questions\u003c\/h2\u003e\n\u003cdiv class=\"hdiy-faq\"\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWhat does M3×4.5mm mean, and how do I confirm this is the right size?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eM3 refers to a 3mm nominal thread diameter (approximately 0.118\"). The 4.5mm (approximately 3\/16\") is the grip length — the threaded shank length below the head. Measure your threaded hole depth and clearance before ordering. If you need a longer shank, see our other thumb screw listings.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eHow strong are these thumb screws? Can they handle vibration?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eBrass thumb screws are generally suitable for light-duty clamping and adjustment applications. They are not intended for high-torque or structural load-bearing use. For vibration-prone assemblies, consider adding a lock washer or thread-locking compound.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eCan these be used outdoors or in humid environments?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eBrass has naturally good corrosion resistance compared to plain steel. The nickel-plated variant offers additional surface protection against moisture and mild chemicals. For prolonged outdoor exposure, applying a light coat of protective oil is generally recommended.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWhat thread standard do these use — metric or imperial?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eThese are metric M3 thread screws with a standard M3 pitch (typically 0.5mm). They are \u003cstrong\u003enot\u003c\/strong\u003e compatible with imperial #4-40 or #6-32 threads. Confirm your equipment uses M3 metric threading before ordering.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWhat is the difference between the natural brass and the nickel-plated version?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eBoth variants share the same M3×4.5mm dimensions and knurled flat-head design. The natural brass has a warm golden appearance and develops a patina over time. The nickel-plated version has a silver-toned finish with added surface hardness and slightly better resistance to tarnishing.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWhich pack size should I order?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eFor single-device adjustments (e.g., one slingshot sight), 2–5pcs is typically sufficient. For workshop stock or multi-unit builds, the 20–100pcs packs offer a lower per-piece cost. Check the price-per-piece across pack sizes to find the best value for your project.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eDo I need any tools to install these thumb screws?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eNo tools are required for typical hand-tightening applications — that is the primary purpose of the knurled head design. The knurling pattern provides grip for finger-tightening. If additional torque is needed, a flat-blade screwdriver can generally be used on the head rim.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"hdiy-cta\"\u003e🛒 Select your \u003cstrong\u003efinish and pack quantity\u003c\/strong\u003e above, then add to cart — ships from our US warehouse.\u003c\/div\u003e\n\u003c\/div\u003e","brand":"HomeDIYer","offers":[{"title":"Brass \/ M3×4.5 \/ 2pcs","offer_id":52292919197970,"sku":"LFL01876x2","price":1.99,"currency_code":"USD","in_stock":true},{"title":"Brass \/ M3×4.5 \/ 5pcs","offer_id":52292919230738,"sku":"LFL01876x5","price":2.28,"currency_code":"USD","in_stock":true},{"title":"Brass \/ M3×4.5 \/ 10pcs","offer_id":52292919263506,"sku":"LFL01876x10","price":2.75,"currency_code":"USD","in_stock":true},{"title":"Brass \/ M3×4.5 \/ 20pcs","offer_id":52292919296274,"sku":"LFL01876x20","price":4.3,"currency_code":"USD","in_stock":true},{"title":"Brass \/ M3×4.5 \/ 50pcs","offer_id":52292919329042,"sku":"LFL01876x50","price":9.47,"currency_code":"USD","in_stock":true},{"title":"Brass \/ M3×4.5 \/ 100pcs","offer_id":52292919361810,"sku":"LFL01876x100","price":18.07,"currency_code":"USD","in_stock":true},{"title":"Brass \/ M3×4.5 （Ni-Plated） \/ 2pcs","offer_id":52292919394578,"sku":"LFL01877x2","price":1.99,"currency_code":"USD","in_stock":true},{"title":"Brass \/ M3×4.5 （Ni-Plated） \/ 5pcs","offer_id":52292919427346,"sku":"LFL01877x5","price":2.28,"currency_code":"USD","in_stock":true},{"title":"Brass \/ M3×4.5 （Ni-Plated） \/ 10pcs","offer_id":52292919460114,"sku":"LFL01877x10","price":2.86,"currency_code":"USD","in_stock":true},{"title":"Brass \/ M3×4.5 （Ni-Plated） \/ 20pcs","offer_id":52292919492882,"sku":"LFL01877x20","price":4.46,"currency_code":"USD","in_stock":true},{"title":"Brass \/ M3×4.5 （Ni-Plated） \/ 50pcs","offer_id":52292919525650,"sku":"LFL01877x50","price":9.75,"currency_code":"USD","in_stock":true},{"title":"Brass \/ M3×4.5 （Ni-Plated） \/ 100pcs","offer_id":52292919558418,"sku":"LFL01877x100","price":18.74,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0884\/8936\/1682\/files\/Picture1of7_30e06568-b220-4ce9-bfe9-44c38f33b8eb.jpg?v=1781164875","url":"https:\/\/homediyer.com\/de\/products\/brass-knurled-thumb-screws-m3x4-5mm-flat-head","provider":"HomeDIYer","version":"1.0","type":"link"}