HardLock’s M6 SS400 nuts were completely changed to HL-R in July. No other products, sizes or materials were changed.
The dimensions of the HL-R M6 concave and convex nuts have been changed. Because the dimensions differ on the fitting portion of the current HLN M6 concave and convex nuts, care should be taken to keep them separate.
We will be providing more details on HL-R separately. HL-R is an improved bolt type, incorporating a HARDLOCK nut rim (a flange on the seating face of the concave nut) for better workability. For a comparison, click here (in Japanese).