Hex Head Bolt Assembly with Spring Lock Washer

Product Description:

We run Hex Head Bolt Assembly with Spring Lock Washer from stainless steel, steel or alloy steel, usually heat-treated to Grade 8.8 or 10.9, though we can go to 12.9 if your application calls for it. The spring washer is the split-coil type – those sharp edges are meant to dig in slightly under torque, which is what stops the bolt from backing out under vibration. Underneath it, the flat washer does the job of spreading the clamp force so you do not mark up softer materials like aluminum housings. We roll the threads after heat treatment. This sequence gives us better fatigue life and cleaner gauge fit than rolling before hardening. A light passivation or oil dip goes on each assembly before packaging – enough to keep rust off during ocean transit, but nothing that interferes with torque readings. The critical dimensions we watch closely are the spring washer’s free height and coil angle. A 0.2mm shift there changes the bite characteristics noticeably. That said, we have run this design through 72 hours of bench vibration with less than half a degree of rotation loss, so for most jobs the washer alone is sufficient. Heavy equipment or overhead installations might benefit from a drop of thread-locker during fit-up, but that is your call.

Specification:

Products Details:

The Hex Head Bolt Assembly with Spring Lock Washer is cold-forged rather than cut from bar, because cold-forging keeps the grain structure intact, which means the head does not snap off when you really crank it down. Underneath that head, you will notice a slight serrated pattern. That is there on purpose—it grips the spring washer so it does not spin sideways during tightening. Now the spring washer itself: we use rectangular wire instead of round. That gives you more reactive force from the same diameter, plain and simple. Coating is a zinc trivalent, clear or yellow, and we can get you anywhere from 72 to 120 hours of salt spray resistance depending on how heavy we lay it on. The bolt tip has a chamfered thread entry, which helps operators start it by hand in blind holes without cross-threading—a small detail that saves a surprising amount of time on busy lines. We also keep CMM reports on every lot, available whenever you ask.

Product Feature:

• Cold-forged Hex Head Bolt Assembly with Spring Lock Washer with serrated underside – grips the spring washer during tightening, prevents spinning

• Rectangular-wire spring washer – delivers better spring-back than round wire of the same diameter

• Threads rolled after heat treatment – smoother finish, better fatigue life, consistent gauge fit

• Pre-assembled and bagged – no loose washers on your line, fewer handling errors

• Multiple coating options – zinc-plated, hot-dip galvanized, or oil finish to match your environment

• Full traceability – lot code on every box, traceable to heat number and production shift

Product Application:

• Hex Head Bolt Assembly with Spring Lock Washer used for construction & mining gear – track shoes, bucket teeth, pivot pins. Takes shock loads better than plain bolts.

• Farm machinery – tractors and attachments. Holds through dust, mud, and vibration all season.

• Conveyor systems – frames and motor mounts. One loose bolt shuts down the whole line.

• Automotive chassis & suspension – subframes, control arms. Safety-critical, no loosening issues reported.

• HVAC & compressors – holds tension through heating and cooling cycles.

• Electrical enclosures – maintains grounding, stops door hardware from loosening.

• Plant maintenance – one assembly fits multiple brands. Saves parts clutter.