{"title":"DIN 6916 300HV Structural Washer Black","description":"\u003ch1\u003eDIN 6916 300HV Structural Washer — 45# Carbon Steel, Black Oxide Finish\u003c\/h1\u003e\n\n\u003cp\u003eFULLERKREG DIN 6916 hardened structural washers are manufactured to DIN 6916 standard (equivalent: ISO 7416, DIN EN 14399-6) in 45# medium carbon steel, quenched and tempered to 300–370 HV hardness, with a black oxide (blackening) surface finish. DIN 6916 washers are specifically designed for use in high-tensile structural bolted connections (HV \/ HSFG assemblies) with high-strength bolts of property class 10.9. The washer features 45° chamfers on both inner and outer edges, and is marked H\/HV per DIN 522 for identification in structural assemblies. The black oxide finish provides a uniform matte black appearance with light corrosion protection — suitable for indoor structural applications and assemblies where a black finish is specified or preferred. Black oxide does not affect dimensional tolerances or hardness.\u003c\/p\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eProduct Highlights\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eStandard:\u003c\/strong\u003e DIN 6916 — equivalent to ISO 7416, DIN EN 14399-6\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e 45# Medium Carbon Steel (quenched \u0026amp; tempered)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSurface Treatment:\u003c\/strong\u003e Black Oxide (Blackening)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eHardness:\u003c\/strong\u003e 300–370 HV (Product Grade A, per DIN 522)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSize Range:\u003c\/strong\u003e M12 – M36\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eProfile:\u003c\/strong\u003e Round, chamfered — 45° external chamfer (e) + 45° internal chamfer (c)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMarking:\u003c\/strong\u003e H \/ HV per DIN 522 — required for structural assembly identification\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eUsed with:\u003c\/strong\u003e High-strength bolts property class 10.9 in HV structural connections\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBlack oxide finish:\u003c\/strong\u003e Uniform matte black appearance, light corrosion protection, no dimensional impact\u003c\/li\u003e\n  \u003cli\u003e\u003cstrong\u003eRoHS \u0026amp; REACH Compliant\u003c\/strong\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eDimensional Specifications — DIN 6916, 45# Carbon Steel Black\u003c\/h2\u003e\n\u003cp\u003eAll dimensions in millimeters (mm). Per DIN 6916 \/ ISO 7416. Black oxide adds \u0026lt;1 μm — no dimensional impact.\u003c\/p\u003e\n\n\u003ctable\u003e\n  \u003cthead\u003e\n    \u003ctr\u003e\n\u003cth\u003eFor Thread\u003c\/th\u003e\n\u003cth\u003ed1 min\u003c\/th\u003e\n\u003cth\u003ed1 max\u003c\/th\u003e\n\u003cth\u003ed2 min\u003c\/th\u003e\n\u003cth\u003ed2 max\u003c\/th\u003e\n\u003cth\u003eh min\u003c\/th\u003e\n\u003cth\u003eh max\u003c\/th\u003e\n\u003cth\u003ee min\u003c\/th\u003e\n\u003cth\u003ee max\u003c\/th\u003e\n\u003cth\u003ec min\u003c\/th\u003e\n\u003cth\u003ec max\u003c\/th\u003e\n\u003c\/tr\u003e\n  \u003c\/thead\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n\u003ctd\u003eM12\u003c\/td\u003e\n\u003ctd\u003e13.00\u003c\/td\u003e\n\u003ctd\u003e13.27\u003c\/td\u003e\n\u003ctd\u003e23.48\u003c\/td\u003e\n\u003ctd\u003e24.00\u003c\/td\u003e\n\u003ctd\u003e2.7\u003c\/td\u003e\n\u003ctd\u003e3.3\u003c\/td\u003e\n\u003ctd\u003e0.50\u003c\/td\u003e\n\u003ctd\u003e1.00\u003c\/td\u003e\n\u003ctd\u003e1.6\u003c\/td\u003e\n\u003ctd\u003e1.9\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eM14\u003c\/td\u003e\n\u003ctd\u003e15.00\u003c\/td\u003e\n\u003ctd\u003e15.27\u003c\/td\u003e\n\u003ctd\u003e27.48\u003c\/td\u003e\n\u003ctd\u003e28.00\u003c\/td\u003e\n\u003ctd\u003e2.7\u003c\/td\u003e\n\u003ctd\u003e3.3\u003c\/td\u003e\n\u003ctd\u003e0.50\u003c\/td\u003e\n\u003ctd\u003e1.00\u003c\/td\u003e\n\u003ctd\u003e1.6\u003c\/td\u003e\n\u003ctd\u003e1.9\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eM16\u003c\/td\u003e\n\u003ctd\u003e17.00\u003c\/td\u003e\n\u003ctd\u003e17.27\u003c\/td\u003e\n\u003ctd\u003e29.48\u003c\/td\u003e\n\u003ctd\u003e30.00\u003c\/td\u003e\n\u003ctd\u003e3.7\u003c\/td\u003e\n\u003ctd\u003e4.3\u003c\/td\u003e\n\u003ctd\u003e0.75\u003c\/td\u003e\n\u003ctd\u003e1.50\u003c\/td\u003e\n\u003ctd\u003e1.6\u003c\/td\u003e\n\u003ctd\u003e1.9\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eM18\u003c\/td\u003e\n\u003ctd\u003e19.00\u003c\/td\u003e\n\u003ctd\u003e19.33\u003c\/td\u003e\n\u003ctd\u003e33.38\u003c\/td\u003e\n\u003ctd\u003e34.00\u003c\/td\u003e\n\u003ctd\u003e3.7\u003c\/td\u003e\n\u003ctd\u003e4.3\u003c\/td\u003e\n\u003ctd\u003e0.75\u003c\/td\u003e\n\u003ctd\u003e1.50\u003c\/td\u003e\n\u003ctd\u003e2.0\u003c\/td\u003e\n\u003ctd\u003e2.5\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eM20\u003c\/td\u003e\n\u003ctd\u003e21.00\u003c\/td\u003e\n\u003ctd\u003e21.33\u003c\/td\u003e\n\u003ctd\u003e36.38\u003c\/td\u003e\n\u003ctd\u003e37.00\u003c\/td\u003e\n\u003ctd\u003e3.7\u003c\/td\u003e\n\u003ctd\u003e4.3\u003c\/td\u003e\n\u003ctd\u003e0.75\u003c\/td\u003e\n\u003ctd\u003e1.50\u003c\/td\u003e\n\u003ctd\u003e2.0\u003c\/td\u003e\n\u003ctd\u003e2.5\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eM22\u003c\/td\u003e\n\u003ctd\u003e23.00\u003c\/td\u003e\n\u003ctd\u003e23.33\u003c\/td\u003e\n\u003ctd\u003e38.38\u003c\/td\u003e\n\u003ctd\u003e39.00\u003c\/td\u003e\n\u003ctd\u003e3.7\u003c\/td\u003e\n\u003ctd\u003e4.3\u003c\/td\u003e\n\u003ctd\u003e0.75\u003c\/td\u003e\n\u003ctd\u003e1.50\u003c\/td\u003e\n\u003ctd\u003e2.0\u003c\/td\u003e\n\u003ctd\u003e2.5\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eM24\u003c\/td\u003e\n\u003ctd\u003e25.00\u003c\/td\u003e\n\u003ctd\u003e25.00\u003c\/td\u003e\n\u003ctd\u003e43.38\u003c\/td\u003e\n\u003ctd\u003e44.00\u003c\/td\u003e\n\u003ctd\u003e4.0\u003c\/td\u003e\n\u003ctd\u003e4.4\u003c\/td\u003e\n\u003ctd\u003e0.75\u003c\/td\u003e\n\u003ctd\u003e1.50\u003c\/td\u003e\n\u003ctd\u003e2.0\u003c\/td\u003e\n\u003ctd\u003e2.5\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eM27\u003c\/td\u003e\n\u003ctd\u003e28.00\u003c\/td\u003e\n\u003ctd\u003e28.52\u003c\/td\u003e\n\u003ctd\u003e49.00\u003c\/td\u003e\n\u003ctd\u003e50.00\u003c\/td\u003e\n\u003ctd\u003e4.4\u003c\/td\u003e\n\u003ctd\u003e5.6\u003c\/td\u003e\n\u003ctd\u003e1.00\u003c\/td\u003e\n\u003ctd\u003e2.00\u003c\/td\u003e\n\u003ctd\u003e2.5\u003c\/td\u003e\n\u003ctd\u003e3.0\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eM30\u003c\/td\u003e\n\u003ctd\u003e31.00\u003c\/td\u003e\n\u003ctd\u003e31.62\u003c\/td\u003e\n\u003ctd\u003e54.80\u003c\/td\u003e\n\u003ctd\u003e56.00\u003c\/td\u003e\n\u003ctd\u003e4.4\u003c\/td\u003e\n\u003ctd\u003e5.6\u003c\/td\u003e\n\u003ctd\u003e1.00\u003c\/td\u003e\n\u003ctd\u003e2.00\u003c\/td\u003e\n\u003ctd\u003e2.5\u003c\/td\u003e\n\u003ctd\u003e3.0\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eM36\u003c\/td\u003e\n\u003ctd\u003e37.00\u003c\/td\u003e\n\u003ctd\u003e37.62\u003c\/td\u003e\n\u003ctd\u003e64.80\u003c\/td\u003e\n\u003ctd\u003e66.00\u003c\/td\u003e\n\u003ctd\u003e5.4\u003c\/td\u003e\n\u003ctd\u003e6.6\u003c\/td\u003e\n\u003ctd\u003e1.25\u003c\/td\u003e\n\u003ctd\u003e2.50\u003c\/td\u003e\n\u003ctd\u003e2.5\u003c\/td\u003e\n\u003ctd\u003e3.0\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp\u003e\u003cem\u003eAll dimensions in mm per DIN 6916 \/ ISO 7416. d1 = inner diameter; d2 = outer diameter; h = thickness; e = external chamfer; c = internal chamfer. Both chamfers at 45°. Black oxide coating \u0026lt;1μm — no dimensional impact.\u003c\/em\u003e\u003c\/p\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eBlack Oxide vs. Zinc CR3 — Surface Treatment Comparison\u003c\/h2\u003e\n\u003ctable\u003e\n  \u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eProperty\u003c\/th\u003e\n\u003cth\u003eBlack Oxide (This Product)\u003c\/th\u003e\n\u003cth\u003eZinc CR3\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n\u003ctd\u003eAppearance\u003c\/td\u003e\n\u003ctd\u003eMatte black, uniform\u003c\/td\u003e\n\u003ctd\u003eBright silver\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eCoating thickness\u003c\/td\u003e\n\u003ctd\u003e\u0026lt;1 μm — no dimensional impact\u003c\/td\u003e\n\u003ctd\u003e5–12 μm\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eCorrosion resistance\u003c\/td\u003e\n\u003ctd\u003eLight — indoor \/ dry environments\u003c\/td\u003e\n\u003ctd\u003eGood — ≥72h NSS\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eDimensional impact\u003c\/td\u003e\n\u003ctd\u003eNone\u003c\/td\u003e\n\u003ctd\u003eMinimal (5–12 μm)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eRoHS compliant\u003c\/td\u003e\n\u003ctd\u003eYes\u003c\/td\u003e\n\u003ctd\u003eYes — CR3, no Cr6+\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eBest for\u003c\/td\u003e\n\u003ctd\u003eIndoor structural, black finish specified\u003c\/td\u003e\n\u003ctd\u003eOutdoor \/ light outdoor, corrosion protection\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eMaterial \u0026amp; Mechanical Properties — 45# Carbon Steel, Black Oxide\u003c\/h2\u003e\n\u003ctable\u003e\n  \u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eProperty\u003c\/th\u003e\n\u003cth\u003eValue\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n\u003ctd\u003eMaterial Grade\u003c\/td\u003e\n\u003ctd\u003e45# Medium Carbon Steel (GB\/T 699)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eC Content\u003c\/td\u003e\n\u003ctd\u003e0.42 – 0.50%\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eHeat Treatment\u003c\/td\u003e\n\u003ctd\u003eQuench \u0026amp; Temper\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eHardness\u003c\/td\u003e\n\u003ctd\u003e300–370 HV (Product Grade A)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eSurface Treatment\u003c\/td\u003e\n\u003ctd\u003eBlack Oxide (Blackening)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eCoating thickness\u003c\/td\u003e\n\u003ctd\u003e\u0026lt;1 μm\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eProduct marking\u003c\/td\u003e\n\u003ctd\u003eH \/ HV per DIN 522\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eEquivalent standards\u003c\/td\u003e\n\u003ctd\u003eISO 7416 · DIN EN 14399-6 · PN 82039 · UNI 5714 · EU 784\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eUsed with bolt class\u003c\/td\u003e\n\u003ctd\u003eProperty class 10.9 (HV structural bolting)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eRoHS \/ REACH\u003c\/td\u003e\n\u003ctd\u003eCompliant\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eWhy High Hardness (300–370 HV) Is Required for Structural Washers\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eEmbedding prevention:\u003c\/strong\u003e High-tensile structural bolts (class 10.9) are tightened to very high preloads. A soft washer would embed into the connected steel surface, reducing clamping force and compromising joint integrity\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eLoad distribution:\u003c\/strong\u003e The hardened washer distributes the high bolt head\/nut bearing load over a larger area without deforming\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eChamfer function:\u003c\/strong\u003e The 45° external chamfer (e) accommodates the bolt head\/nut fillet radius; the 45° internal chamfer (c) accommodates the bolt shank thread runout\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eH\/HV marking:\u003c\/strong\u003e Required by DIN 6916 \/ DIN EN 14399-6 for traceability and inspection in structural assemblies\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eDIN 6916 vs. DIN 125 — Key Differences\u003c\/h2\u003e\n\u003ctable\u003e\n  \u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eFeature\u003c\/th\u003e\n\u003cth\u003eDIN 6916 (Structural)\u003c\/th\u003e\n\u003cth\u003eDIN 125 (Standard)\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n\u003ctd\u003eHardness\u003c\/td\u003e\n\u003ctd\u003e300–370 HV (hardened)\u003c\/td\u003e\n\u003ctd\u003e100–200 HV (soft)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eChamfer\u003c\/td\u003e\n\u003ctd\u003e45° inner \u0026amp; outer chamfer\u003c\/td\u003e\n\u003ctd\u003eNo chamfer\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eMarking\u003c\/td\u003e\n\u003ctd\u003eH \/ HV required\u003c\/td\u003e\n\u003ctd\u003eNone\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eUsed with\u003c\/td\u003e\n\u003ctd\u003eClass 10.9 HV structural bolts\u003c\/td\u003e\n\u003ctd\u003eGeneral bolted assemblies\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eStandard\u003c\/td\u003e\n\u003ctd\u003eDIN 6916 \/ ISO 7416 \/ EN 14399-6\u003c\/td\u003e\n\u003ctd\u003eDIN 125 \/ ISO 7089\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eEmbedding resistance\u003c\/td\u003e\n\u003ctd\u003eHigh — no embedding under preload\u003c\/td\u003e\n\u003ctd\u003eLow — may embed under high load\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eApplication Scenarios\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eIndoor high-tensile structural bolting (HV)\u003c\/strong\u003e — steel frame connections with class 10.9 bolts, black finish preferred\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSteel buildings \u0026amp; industrial structures\u003c\/strong\u003e — interior column and beam connections\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMachinery \u0026amp; equipment frames\u003c\/strong\u003e — high-preload bolted joints where black finish is specified\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eArchitectural steelwork\u003c\/strong\u003e — exposed structural connections where black appearance is required\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eGeneral HV structural connections\u003c\/strong\u003e — wherever black oxide DIN 6916 washers are specified\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eProduct Photo Gallery\u003c\/h2\u003e\n\u003cp\u003eFULLERKREG DIN 6916 300HV Structural Washer, 45# Carbon Steel, Black Oxide:\u003c\/p\u003e\n\u003ctable\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n      \u003ctd style=\"width:25%;text-align:center;padding:12px\"\u003e[ Photo 1 ]\u003c\/td\u003e\n      \u003ctd style=\"width:25%;text-align:center;padding:12px\"\u003e[ Photo 2 ]\u003c\/td\u003e\n      \u003ctd style=\"width:25%;text-align:center;padding:12px\"\u003e[ Photo 3 ]\u003c\/td\u003e\n      \u003ctd style=\"width:25%;text-align:center;padding:12px\"\u003e[ Photo 4 ]\u003c\/td\u003e\n    \u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eWhy Choose FULLERKREG?\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e🏭 \u003cstrong\u003eDirect manufacturer\u003c\/strong\u003e — factory in China, no middlemen\u003c\/li\u003e\n  \u003cli\u003e📐 \u003cstrong\u003eStrict DIN dimensional control\u003c\/strong\u003e — 100% inspection on dimensions and hardness\u003c\/li\u003e\n  \u003cli\u003e🌍 \u003cstrong\u003eGlobal export experience\u003c\/strong\u003e — serving distributors in Europe, North America, Southeast Asia\u003c\/li\u003e\n  \u003cli\u003e📦 \u003cstrong\u003eFlexible MOQ\u003c\/strong\u003e — small trial orders and large bulk shipments both welcome\u003c\/li\u003e\n  \u003cli\u003e📋 \u003cstrong\u003eFull documentation\u003c\/strong\u003e — material certs, hardness reports, RoHS declarations available\u003c\/li\u003e\n  \u003cli\u003e⚡ \u003cstrong\u003eFast lead times\u003c\/strong\u003e — standard sizes in stock, ready to ship\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: What is black oxide finish?\u003c\/strong\u003e\u003cbr\u003e\nA: Black oxide (blackening) is a chemical conversion coating that produces a uniform matte black iron oxide layer (\u0026lt;1 μm thick) on the steel surface. It provides light corrosion protection and a black appearance without affecting dimensions or hardness. Suitable for indoor and dry environments; not recommended for outdoor or high-humidity applications without additional oil or wax treatment.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: What is DIN 6916?\u003c\/strong\u003e\u003cbr\u003e\nA: DIN 6916 specifies hardened round washers for high-tensile structural bolting (HV connections). Equivalent to ISO 7416 and DIN EN 14399-6. Hardness 300–370 HV, with 45° inner and outer chamfers, marked H\/HV. Used with property class 10.9 bolts in structural steel connections.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: When should I choose black oxide over zinc CR3?\u003c\/strong\u003e\u003cbr\u003e\nA: Choose black oxide when a black appearance is required or specified, and the application is indoor or dry. Choose zinc CR3 when corrosion protection is needed for outdoor or humid environments (≥72h NSS).\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: Does black oxide affect dimensions or hardness?\u003c\/strong\u003e\u003cbr\u003e\nA: No. Black oxide coating is \u0026lt;1 μm thick — negligible dimensional impact. Hardness (300–370 HV) is achieved by quench and temper before blackening and is not affected by the surface treatment.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eQ: Do you provide material test certificates?\u003c\/strong\u003e\u003cbr\u003e\nA: Yes. Mill certificates, hardness test reports, and RoHS declarations available upon request.\u003c\/p\u003e\n\n\u003chr\u003e\n\n\u003cp\u003e\u003cstrong\u003eFULLERKREG Fasteners\u003c\/strong\u003e — Precision DIN Standard Fasteners, Direct from Manufacturer.\u003cbr\u003e\nFor wholesale inquiries, technical questions, or custom orders, please contact our sales team.\u003c\/p\u003e","products":[],"url":"https:\/\/www.fullerkr.com\/collections\/din-6916-300hv-structural-washer-black.oembed","provider":"Fullerkreg Fasteners","version":"1.0","type":"link"}