Nord-Lock NL12sp wedge-locking washer pair for M12 bolt, 316 stainless steel. Two washers per pair with cam-face design where the cam angle exceeds the bolt thread pitch — vibration LOOSENING is mechanically prevented. Certified to DIN 25201-4 (junker vibration test). Marine, offshore, wind-turbine, rail and heavy-duty machinery bolted joints subject to vibration or dynamic loading. Nord-Lock P/N NL12sp (spring pass); equivalent to Heico-Lock HKD-12. NL8sp (M8), NL10sp (M10), NL16sp (M16) also stocked.