{"product_id":"m3-m4-m5-hex-socket-countersunk-screws-304-stainless-steel-din7991","title":"M3 M4 M5 Hex Socket Countersunk Screws 304 Stainless Steel Flat Head DIN7991","description":"\u003cdiv class=\"hdiy-desc\"\u003e\n\n\u003cdiv class=\"hdiy-overview\"\u003e\n  \u003ch2\u003eM3 M4 M5 Hex Socket Countersunk Screws — DIN7991 Precision Fasteners in 304 Stainless Steel\u003c\/h2\u003e\n  \u003cp\u003eStripped Phillips heads and mismatched fasteners slow down every project. These DIN7991 hex socket countersunk screws give repair technicians, fabricators, and serious DIYers a reliable, flush-fitting fastener that stays put — even under high torque.\u003c\/p\u003e\n  \u003cp\u003eEach screw is precision-machined from 304 stainless steel to DIN7991 specifications, featuring a flat countersunk head with a 90° angle and an internal hex (Allen key) drive. Available in M3, M4, and M5 thread sizes across multiple lengths — M3 from 8 mm to 20 mm (approx. 0.31\"–0.79\"), M4 from 6 mm to 20 mm (approx. 0.24\"–0.79\"), and M5 from 8 mm to 20 mm (approx. 0.31\"–0.79\"). Thread pitches are M3 × 0.5 mm, M4 × 0.7 mm, and M5 × 0.8 mm.\u003c\/p\u003e\n  \u003cp\u003eWhether you're assembling aluminum extrusions, mounting electronics panels, building furniture, or working on automotive trim, these M3 M4 M5 hex socket countersunk screws deliver a clean, flush finish and consistent performance across every application.\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  Compatible with standard DIN 911 hex (Allen) keys — fits M3, M4, and M5 threaded holes in metal, wood, and plastic assemblies\n\u003c\/div\u003e\n\n\u003cdiv\u003e\n  \u003ch2\u003e✅ Key Features of These Hex Socket Countersunk Screws\u003c\/h2\u003e\n  \u003cul class=\"hdiy-features\"\u003e\n    \u003cli\u003e\n      \u003cspan class=\"hdiy-icon\"\u003e🔩\u003c\/span\u003e\n      \u003cspan\u003e\u003cstrong\u003eDIN7991 Precision Standard:\u003c\/strong\u003e Manufactured to DIN7991 specifications for exact dimensional accuracy — consistent head diameter, thread pitch, and countersunk angle across every size and length.\u003c\/span\u003e\n    \u003c\/li\u003e\n    \u003cli\u003e\n      \u003cspan class=\"hdiy-icon\"\u003e🛡️\u003c\/span\u003e\n      \u003cspan\u003e\u003cstrong\u003e304 Stainless Steel Construction:\u003c\/strong\u003e Corrosion-resistant 304 stainless steel handles humid, outdoor, and light marine environments without rusting or degrading over time.\u003c\/span\u003e\n    \u003c\/li\u003e\n    \u003cli\u003e\n      \u003cspan class=\"hdiy-icon\"\u003e🔧\u003c\/span\u003e\n      \u003cspan\u003e\u003cstrong\u003eHex Socket (Allen Key) Drive:\u003c\/strong\u003e Internal hex drive delivers higher torque capacity than Phillips or slotted drives, reduces cam-out risk, and works with standard DIN 911 hex keys.\u003c\/span\u003e\n    \u003c\/li\u003e\n    \u003cli\u003e\n      \u003cspan class=\"hdiy-icon\"\u003e📐\u003c\/span\u003e\n      \u003cspan\u003e\u003cstrong\u003eFlat Countersunk Head:\u003c\/strong\u003e 90° countersunk head sits flush with or below the surface for a clean, snag-free finish — ideal for panels, enclosures, and visible assemblies.\u003c\/span\u003e\n    \u003c\/li\u003e\n    \u003cli\u003e\n      \u003cspan class=\"hdiy-icon\"\u003e📏\u003c\/span\u003e\n      \u003cspan\u003e\u003cstrong\u003eWide Size Selection:\u003c\/strong\u003e 15 size variants across M3, M4, and M5 threads in lengths from 6 mm to 20 mm — select the exact size you need without buying bulk assortments.\u003c\/span\u003e\n    \u003c\/li\u003e\n    \u003cli\u003e\n      \u003cspan class=\"hdiy-icon\"\u003e⚙️\u003c\/span\u003e\n      \u003cspan\u003e\u003cstrong\u003ePrecision-Machined Threads:\u003c\/strong\u003e Consistent thread pitch (M3 × 0.5 mm \/ M4 × 0.7 mm \/ M5 × 0.8 mm) ensures smooth engagement and a secure, vibration-resistant hold.\u003c\/span\u003e\n    \u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/div\u003e\n\n\u003cdiv class=\"hdiy-usecases\"\u003e\n  \u003ch2\u003e🎯 Who Is This For?\u003c\/h2\u003e\n  \u003cdiv class=\"hdiy-usecase-item\"\u003e\n    \u003cspan\u003e🏭\u003c\/span\u003e\n    \u003cstrong\u003eFabricators \u0026amp; Machine Builders\u003c\/strong\u003e\n    \u003cp\u003eFlush-mount panels, guards, and covers on aluminum extrusions or steel frames with a fastener that meets DIN7991 dimensional standards.\u003c\/p\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"hdiy-usecase-item\"\u003e\n    \u003cspan\u003e💻\u003c\/span\u003e\n    \u003cstrong\u003eElectronics \u0026amp; Enclosure Assembly\u003c\/strong\u003e\n    \u003cp\u003eSecure PCB standoffs, enclosure lids, and rack-mount panels with M3 or M4 hex socket screws that won't strip under repeated assembly cycles.\u003c\/p\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"hdiy-usecase-item\"\u003e\n    \u003cspan\u003e🪑\u003c\/span\u003e\n    \u003cstrong\u003eFurniture \u0026amp; Woodworking\u003c\/strong\u003e\n    \u003cp\u003eInstall hardware, hinges, and metal inserts with a countersunk screw that disappears into the surface for a professional, furniture-grade finish.\u003c\/p\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"hdiy-usecase-item\"\u003e\n    \u003cspan\u003e🔨\u003c\/span\u003e\n    \u003cstrong\u003eDIY Home Improvement\u003c\/strong\u003e\n    \u003cp\u003eKeep a selection of M3–M5 hex socket screws on hand for general repairs, custom brackets, and mounting tasks around the workshop or garage.\u003c\/p\u003e\n  \u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003cdiv class=\"hdiy-table-wrap\"\u003e\n  \u003ctable\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n\u003cth\u003eStandard\u003c\/th\u003e\n\u003ctd\u003eDIN7991\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\u003eHead Style\u003c\/th\u003e\n\u003ctd\u003eFlat Countersunk Head\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003cth\u003eDrive Style\u003c\/th\u003e\n\u003ctd\u003eHex Socket (Allen Key \/ Internal Hex)\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003cth\u003eThread Sizes\u003c\/th\u003e\n\u003ctd\u003eM3 \/ M4 \/ M5\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003cth\u003eThread Pitch\u003c\/th\u003e\n\u003ctd\u003eM3 × 0.5 mm | M4 × 0.7 mm | M5 × 0.8 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003cth\u003eHead Diameter\u003c\/th\u003e\n\u003ctd\u003eM3: 5.7 mm | M4: 7.6 mm | M5: 9.5 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003cth\u003eAvailable Lengths\u003c\/th\u003e\n\u003ctd\u003eM3: 8–20 mm | M4: 6–20 mm | M5: 8–20 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003cth\u003eHex Key Size\u003c\/th\u003e\n\u003ctd\u003eDIN 911 compatible (see variant for exact size)\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003cth\u003eFinish\u003c\/th\u003e\n\u003ctd\u003eNatural Stainless (Brushed)\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  \u003cdetails\u003e\n    \u003csummary\u003eWhat standard do these screws conform to?\u003c\/summary\u003e\n    \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eThese screws are manufactured to DIN7991, the German standard for hexagon socket countersunk head screws. This ensures consistent head geometry, thread pitch, and dimensional tolerances across all sizes.\u003c\/p\u003e\u003c\/div\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhat hex key size do I need to drive these screws?\u003c\/summary\u003e\n    \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eThese screws use a standard internal hex (Allen key) drive compatible with DIN 911 hex keys. Typically M3 uses a 2 mm key, M4 uses a 2.5 mm key, and M5 uses a 3 mm key — however, we recommend verifying with your specific hex key set before use.\u003c\/p\u003e\u003c\/div\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eAre these screws suitable for outdoor or marine use?\u003c\/summary\u003e\n    \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003e304 stainless steel offers good corrosion resistance for outdoor and moderately humid environments. For full marine or saltwater immersion applications, 316 stainless steel is generally recommended.\u003c\/p\u003e\u003c\/div\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhat is the countersunk head angle?\u003c\/summary\u003e\n    \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003ePer DIN7991, these screws have a 90° countersunk head angle, which is the standard for most countersunk holes in metal and wood applications.\u003c\/p\u003e\u003c\/div\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eCan I use these in aluminum, steel, or plastic?\u003c\/summary\u003e\n    \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eYes. These hex socket countersunk screws are suitable for use in aluminum, mild steel, and rigid plastic substrates. Always ensure the receiving material has the correct threaded hole or insert for the chosen size.\u003c\/p\u003e\u003c\/div\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eDo you sell these in bulk quantities?\u003c\/summary\u003e\n    \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eEach listing is sold per piece. Select your required size from the variant options above and adjust the quantity at checkout. Contact us if you need larger bulk orders.\u003c\/p\u003e\u003c\/div\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhat is the difference between M3, M4, and M5 thread sizes?\u003c\/summary\u003e\n    \u003cdiv class=\"hdiy-faq-body\"\u003e\u003cp\u003eM3, M4, and M5 refer to the nominal outer thread diameter: 3 mm, 4 mm, and 5 mm respectively. Each size also has a specific thread pitch — M3 × 0.5 mm, M4 × 0.7 mm, M5 × 0.8 mm — which must match the threaded hole or nut being used.\u003c\/p\u003e\u003c\/div\u003e\n  \u003c\/details\u003e\n\u003c\/div\u003e\n\n\u003cdiv class=\"hdiy-cta\"\u003e🛒 Select your Size above, then add to cart.\u003c\/div\u003e\n\n\u003c\/div\u003e","brand":"HomeDIYer","offers":[{"title":"M3*8mm","offer_id":51169759461650,"sku":"US-KC00020","price":4.14,"currency_code":"USD","in_stock":true},{"title":"M3*10mm","offer_id":51169759494418,"sku":"US-KC00021","price":4.66,"currency_code":"USD","in_stock":true},{"title":"M3*12mm","offer_id":51169759527186,"sku":"US-KC00022","price":5.28,"currency_code":"USD","in_stock":true},{"title":"M3*20mm","offer_id":51169759559954,"sku":"US-KC00023","price":7.33,"currency_code":"USD","in_stock":true},{"title":"M4*6mm","offer_id":51169759592722,"sku":"US-KC00024","price":5.88,"currency_code":"USD","in_stock":true},{"title":"M4*8mm","offer_id":51169759625490,"sku":"US-KC00025","price":6.71,"currency_code":"USD","in_stock":true},{"title":"M4*10mm","offer_id":51169759658258,"sku":"US-KC00026","price":7.65,"currency_code":"USD","in_stock":true},{"title":"M4*12mm","offer_id":51169759691026,"sku":"US-KC00027","price":8.43,"currency_code":"USD","in_stock":true},{"title":"M4*16mm","offer_id":51169759723794,"sku":"US-KC00028","price":10.51,"currency_code":"USD","in_stock":true},{"title":"M4*20mm","offer_id":51169759756562,"sku":"US-KC00029","price":12.13,"currency_code":"USD","in_stock":true},{"title":"M5*8mm","offer_id":51169759789330,"sku":"US-KC00030","price":10.66,"currency_code":"USD","in_stock":true},{"title":"M5*10mm","offer_id":51169759822098,"sku":"US-KC00031","price":12.04,"currency_code":"USD","in_stock":true},{"title":"M5*12mm","offer_id":51169759854866,"sku":"US-KC00032","price":13.56,"currency_code":"USD","in_stock":true},{"title":"M5*16mm","offer_id":51169759887634,"sku":"US-KC00033","price":16.45,"currency_code":"USD","in_stock":true},{"title":"M5*20mm","offer_id":51169759920402,"sku":"US-KC00034","price":19.44,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0884\/8936\/1682\/files\/Main-06_44974cd4-fa87-41bf-ab89-9cc48f4b8416.jpg?v=1762199943","url":"https:\/\/homediyer.com\/products\/m3-m4-m5-hex-socket-countersunk-screws-304-stainless-steel-din7991","provider":"HomeDIYer","version":"1.0","type":"link"}