Securfix Nylon Locking Nut Zinc Plated M8Securfix Nylon Locking Nut Zinc Plated M8Manufacturer: securfix SKU: 5019923004632 £3.49 Qty: Add to cart Ship toSelect countryUnited Kingdom *Other *Shipping MethodNameEstimated DeliveryPriceNo shipping optionsApply Custom wishlist OKAdd to wishlistAdd to compare listEmail a friendThey have a nylon insert, or collar, which is smaller than the thread diameter. As the nylon insert lock nut is tightened, the collar deforms over the mating diameter, creating friction