Left Hand Thread DIN6923 304 Stainless Steel Hex Serrated Flange Lock Nut M4–M12

Left Hand Thread DIN6923 304 Stainless Steel Hex Serrated Flange Lock Nut — M4–M12

Left hand thread DIN6923 stainless steel hex serrated flange lock nuts are specified wherever a standard right-hand thread nut would loosen due to counter-clockwise rotation of the mating shaft or component. The reverse (left-hand) thread tightens as the shaft rotates counter-clockwise, providing self-tightening anti-loosening performance in rotating machinery, motor shafts, and bicycle pedals. The integrated serrated flange provides additional anti-rotation grip on the mating surface.

Key Specifications

Why Choose Left Hand Thread Flange Lock Nuts?

• Left hand thread — tightens counter-clockwise; self-tightening on shafts that rotate counter-clockwise (left-hand side of rotating machinery)
• Serrated flange — additional mechanical anti-loosening on top of left-hand thread’s inherent self-tightening; double protection against loosening
• 304 A2 stainless — corrosion-resistant for outdoor, marine, and industrial rotating machinery
• DIN6923 standard — internationally specified flange nut geometry; compatible with left-hand thread bolts and studs of the same pitch
• M4–M12 range — covers the most common rotating machinery and motor shaft sizes

Typical Applications

• Electric motor shaft retention (left-hand side of motor — counter-clockwise rotation)
• Bicycle left pedal thread (standard left-hand thread on left crank arm)
• Angle grinder and power tool spindle lock nuts (left-hand thread standard)
• Lathe and CNC spindle chuck retention (left-hand thread on left-hand spindle)
• Fan and propeller shaft retention on counter-clockwise rotating shafts
• Automotive wheel bearing and hub retention (left-hand thread on left-side wheels, some vehicles)

Compatible With

• Left hand thread metric bolts and studs M4–M12 (LH designation)
• Left hand thread threaded rod M4–M12
• Spanner / socket: M4=7mm, M5=8mm, M6=10mm, M8=13mm, M10=17mm, M12=19mm AF
• Note: NOT compatible with standard right-hand thread bolts — verify thread direction before ordering

Package Contents

• Left hand thread DIN6923 hex serrated flange lock nuts in selected size and quantity (per variant)

Frequently Asked Questions

Q: How do I identify a left hand thread nut?

A: Left hand thread nuts are typically marked with “LH” or a groove/notch on the hex flats. When viewed from the threaded end, a left-hand thread spirals clockwise (opposite to standard right-hand thread). To tighten, turn counter-clockwise; to loosen, turn clockwise — the opposite of a standard nut.

Q: Why does my bicycle left pedal use a left-hand thread?

A: The left pedal uses a left-hand thread so that the pedalling motion (which rotates the crank counter-clockwise when viewed from the left side) self-tightens the pedal rather than loosening it. This is a universal standard on all bicycles.

Q: Can I use a left-hand thread nut on a right-hand thread bolt?

A: No. Left-hand and right-hand thread nuts are not interchangeable. Attempting to thread a LH nut onto a RH bolt will cross-thread and damage both components. Always verify thread direction before installation.