{"product_id":"carbon-steel-metric-hex-key-allen-wrench-0-9mm-4mm","title":"Carbon Steel Metric Allen Keys-Hex Wrench-Hexagon Key 0.9mm - 4mm All Sizes","description":"\u003cdiv class=\"hdiy-desc\"\u003e\n\u003cdiv class=\"hdiy-overview\"\u003e\n\u003ch2\u003eCarbon Steel Metric Hex Keys — Precision Allen Wrench in Every Size from 0.9mm to 4mm\u003c\/h2\u003e\n\u003cp\u003eWhen a stripped or mismatched hex key leaves a bolt half-tightened, the whole project stalls. DIYers, cyclists, and small-appliance technicians who work with fine metric fasteners need a reliable L-key that fits precisely — not one that slips and rounds out the socket. These carbon steel metric Allen keys are sized for the smallest and most commonly overlooked hex bolts, covering the full range from 0.9 mm up to 4 mm.\u003c\/p\u003e\n\u003cp\u003eEach key is machined from carbon steel and finished in either Black oxide or Silver (bright) coating. The L-shape body spans 33–68 mm on the long arm and 11–25 mm on the short arm, depending on the size selected. The hex cross-section measures 0.9 × 0.9 mm up to 4 × 4 mm (Side dimension), giving a snug, torque-efficient fit in metric socket-head cap screws and set screws of the corresponding drive size.\u003c\/p\u003e\n\u003cp\u003eTypical applications include tightening grub screws on bicycle stems and handlebars, adjusting set screws in miniature machinery and power tools, assembling flat-pack furniture with recessed hex bolts, and servicing electronics enclosures or optical equipment where sub-2 mm hex drives are required. Available individually or in multi-packs of up to 50 pieces for workshop stocking or small-batch production use.\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 Fits metric socket-head cap screws, set screws, and grub screws with hex drives from 0.9 mm to 4 mm (ISO 2936 \/ DIN 911 profile). Not for inch (SAE\/Imperial) hex fasteners.\u003c\/div\u003e\n\u003cdiv class=\"hdiy-features\"\u003e\n\u003ch2\u003e✅ Key Features of These Carbon Steel Metric Hex Keys\u003c\/h2\u003e\n\u003cul class=\"hdiy-list\"\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e📐\u003c\/span\u003e\u003cstrong\u003eEight Precise Sizes:\u003c\/strong\u003e Covers 0.9, 1.27, 1.5, 2, 2.5, 3 (two variants), and 4 mm — the full range of fine metric hex drives in a single product line.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🔧\u003c\/span\u003e\u003cstrong\u003eCarbon Steel Construction:\u003c\/strong\u003e Machined from carbon steel for adequate hardness and resistance to deformation under normal torque loads on metric fasteners.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🎨\u003c\/span\u003e\u003cstrong\u003eTwo Finish Options:\u003c\/strong\u003e Black oxide finish for corrosion inhibition in moderate environments; Silver (bright) finish for easy visual identification in a tool tray.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e📏\u003c\/span\u003e\u003cstrong\u003eL-Shape Geometry:\u003c\/strong\u003e Long arm provides reach into recessed cavities; short arm delivers increased torque leverage — standard L-key ergonomics for controlled tightening.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e📦\u003c\/span\u003e\u003cstrong\u003eFlexible Quantity Options:\u003c\/strong\u003e Order 1, 5, 10, 15, 20, 30, or 50 pieces per size — suited for single-use replacement, kit building, or workshop bulk stocking.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e✔️\u003c\/span\u003e\u003cstrong\u003eConsistent Hex Profile:\u003c\/strong\u003e Ground hex faces maintain dimensional accuracy across the full length of the key, reducing the risk of cam-out in tight or deep sockets.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"hdiy-table-wrap\"\u003e\n\u003ch2\u003e📐 Technical Specifications — Metric Hex Key Allen Wrench\u003c\/h2\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eProduct Type\u003c\/th\u003e\n\u003ctd\u003eL-Shape Metric Hex Key (Allen Wrench)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eMaterial\u003c\/th\u003e\n\u003ctd\u003eCarbon Steel\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eFinish \/ Color\u003c\/th\u003e\n\u003ctd\u003eBlack oxide or Silver (bright) — see variant options\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eHex Size Range (Side)\u003c\/th\u003e\n\u003ctd\u003e0.9 mm – 4 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eAvailable Sizes (Side × H × L)\u003c\/th\u003e\n\u003ctd\u003e0.9×11×33 mm, 1.27×17×47 mm, 1.5×17×47 mm, 2×17×50 mm, 2.5×19×53 mm, 3×20×60 mm, 3×21×57 mm, 4×25×68 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eLong Arm Length (L)\u003c\/th\u003e\n\u003ctd\u003e33 mm – 68 mm (varies by size)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eShort Arm Length (H)\u003c\/th\u003e\n\u003ctd\u003e11 mm – 25 mm (varies by size)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eDrive Standard\u003c\/th\u003e\n\u003ctd\u003eMetric (ISO 2936 \/ DIN 911 profile)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eQuantity per Order\u003c\/th\u003e\n\u003ctd\u003eSee variant options (1 \/ 5 \/ 10 \/ 15 \/ 20 \/ 30 \/ 50 PCS)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\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\u003cdiv class=\"hdiy-faq\"\u003e\n\u003ch2\u003e❓ Frequently Asked Questions\u003c\/h2\u003e\n\u003cdetails\u003e\n\u003csummary\u003eHow do I choose the correct hex key size for my fastener?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eMeasure the width across the flats of the hex socket (the opening in the bolt head or set screw). This measurement in millimeters corresponds directly to the hex key size you need. For example, a socket that measures 2 mm across the flats requires a 2 mm hex key. If you are unsure, start with the next size down and work up — a key that is too large will not enter the socket, while one that is too small will slip and damage the drive.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eAre these hex keys suitable for high-torque applications?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eThese carbon steel hex keys are designed for standard torque requirements on metric socket-head cap screws and set screws in the 0.9–4 mm range. For sub-2 mm sizes in particular, the fasteners themselves are the limiting factor — apply only the torque specified by the fastener manufacturer to avoid stripping the socket. They are not intended for impact driver use or for fasteners requiring calibrated torque values in safety-critical assemblies.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWhat is the difference between the Black and Silver finish options?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eThe Black finish is a black oxide coating that provides a degree of corrosion inhibition in dry to moderately humid environments and reduces light reflection, which can be useful in low-light workspaces. The Silver (bright) finish is an uncoated or lightly treated surface that makes the key easier to spot in a cluttered tool tray. Both finishes are available across the same size range; the choice is primarily practical and visual rather than functional.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWill these keys fit SAE (inch) hex fasteners?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eNo. These are metric hex keys sized in millimeters and are not interchangeable with SAE (inch) hex fasteners. While some metric and inch sizes are close in dimension (for example, 3\/32\" ≈ 2.38 mm), using a metric key in an inch socket — or vice versa — risks rounding out the drive. Always use the correct standard for your fasteners.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eCan I use these hex keys on stainless steel or hardened fasteners?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eCarbon steel hex keys can drive stainless steel fasteners under normal torque conditions. However, for hardened or high-tensile fasteners (Grade 12.9 or equivalent), a chrome-vanadium or S2 steel hex key is generally recommended for better durability. For occasional use on stainless fasteners at moderate torque, these keys perform adequately; for repeated heavy-duty use, consider an alloy steel alternative.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eHow many pieces should I order for a workshop or repair kit?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003eFor a general-purpose toolkit, ordering 5–10 pieces of the most commonly used sizes (typically 2 mm, 2.5 mm, and 3 mm) provides a practical buffer against loss or wear. If you are assembling a repair kit for a specific product line — such as bicycles or flat-pack furniture — ordering 20–30 pieces of the sizes specified in your assembly instructions ensures you have stock for multiple units. The 50-piece option is suited for small production runs or resale kits.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWhat does the \"Side × H × L\" dimension notation mean?\u003c\/summary\u003e\n\u003cdiv class=\"hdiy-faq-body\"\u003e\n\u003cp\u003e\"Side\" refers to the hex key size — the width across the flats of the hexagonal cross-section, which must match your fastener's socket. \"H\" is the length of the short arm of the L-shape, used when you need more torque in a confined space. \"L\" is the length of the long arm, used for reach into deep or recessed sockets. For example, \"2 × 17 × 50 mm\" means a 2 mm hex key with a 17 mm short arm and a 50 mm long arm.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"hdiy-cta\"\u003e🛒 Select your Size, Color, and Amount above, then add to cart.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cp\u003e \u003c\/p\u003e","brand":"HomeDIYer","offers":[{"title":"0.9 x 11 x 33 mm \/ Black \/ 1 PCS","offer_id":52378050887954,"sku":"GYJLTJLWJ00271x1","price":1.48,"currency_code":"USD","in_stock":true},{"title":"1.27 x 17 x 47 mm \/ Silver \/ 1 PCS","offer_id":52378050920722,"sku":"GYJLTJLWJ00272x1","price":1.48,"currency_code":"USD","in_stock":true},{"title":"1.5 x 17 x 47 mm \/ Silver \/ 1 PCS","offer_id":52378050953490,"sku":"GYJLTJLWJ00273x1","price":1.48,"currency_code":"USD","in_stock":true},{"title":"2 x 17 x 50 mm \/ Silver \/ 1 PCS","offer_id":52378050986258,"sku":"GYJLTJLWJ00274x1","price":1.48,"currency_code":"USD","in_stock":true},{"title":"2.5 x 19 x 53 mm \/ 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