Hex Flange Bolts for Automotive Structural Joints
Hex Flange Bolts
Hex head bolts with integrated flange — the flange replaces a separate washer, distributes clamp load over the bearing surface, and anti-rotation serrations prevent backing-off under vibration.
Baseline structural fastener across Tier 1 and Tier 2 programmes: engine block, transmission housing, chassis sub-frame, suspension control arms, exhaust manifold, and wheel hub assemblies. Supplied with external hex, Torx®, or combination drive per drawing, to JIS B1189, DIN EN 1665, or ISO 4162.
Why source through Way Fast
We serve Tier 1 and Tier 2 automotive suppliers — primarily to North American OEM programs, including platforms shared with European and Japanese brands — with day-to-day experience handling the documentation and tolerance standards these projects demand.
01 · Multi-source capacity
Working with multiple qualified manufacturing partners — we match each order to the best-fit production line, stabilizing lead times and cost when single-source capacity tightens.
02 · Submission-grade documentation
Full support for PPAP (Levels 1–3), IMDS submission, and RoHS / REACH documentation.
03 · Audited special-process chain
Partners certified to AIAG CQI-9 (heat treat), CQI-11 (plating), and CQI-12 (coating) — covering the full post-processing chain under audited special-process controls.
04 · Multilingual drawing review
Technical drawing review in English, German, Japanese, and Chinese — including ISO 8015 GPS callouts, JIS standards, thread tolerance classes, and coating specifications.
05 · Strength class and coating selection
Property class (8.8 / 10.9 / 12.9), drive type (external hex, Torx®, or combination), serration geometry, thread pitch (coarse / fine), and coating (phosphate-and-oil, zinc flake, Dacromet, Geomet) matched per torque spec, joint material, and service environment — drawing-reviewed against customer torque-to-yield or angular torque spec where applicable.
Family coverage · 3 classes
Selecting across hex flange bolt strength classes
Property class 8.8
General structural · medium-carbon steel
General structural applications — brackets, mounting hardware, non-critical chassis joints. Medium-carbon steel, quenched and tempered. Standard choice for bulk structural fastening where yield strength above 640 MPa is sufficient.
Property class 10.9
Engine and chassis · alloy steel
Engine block, cylinder head (non-torque-to-yield), transmission housing, chassis sub-frame, and suspension mounts. Alloy steel, quenched and tempered — yield strength above 900 MPa. Most common class in Tier 1 automotive assembly.
Property class 12.9
Critical joints · torque-to-yield
High-strength alloy steel for critical joints — cylinder head, main bearing caps, connecting rod bolts, and torque-to-yield applications. Yield strength above 1,080 MPa; often angle-torqued to specification during assembly.
Sizes
M5 – M30 · #10 – 1 1/4″
Lengths
10 – 200 mm · 3/8″ – 8″
Material
Medium-carbon steel or alloy steel (quenched and tempered to property class). Stainless steel (A2 / A4) per customer specification.
Finishes
Phosphate-and-oil, zinc, zinc flake (Dacromet®, Geomet®), zinc-nickel, Delta-Seal®, black oxide, or to customer specification.
Head types
Hex head with serrated flange, hex head with smooth flange, or per drawing.
Drive
External hex (across-flats per ISO / DIN), Torx®, or combination drives per drawing.
Lead times
Quotation and production
Quotation
Within 5–7 business days from receipt of drawing and specifications.
Sample & production
Schedules issued per project.
Send your drawing, property class, and torque spec — strength class, drive, coating, and manufacturer selection matched per programme.
Supplied through qualified manufacturing partners to JIS B1189 / DIN EN 1665 / ISO 4162 specifications. PPAP / IMDS / RoHS / REACH documentation per customer program.
