Silver Nitride Receiver Finish

For years firearms – and particularly over and under shotguns – have been given a variety of finishes on the receiver, and trigger guard components. And although the most common is the black-colored oxidizing finish called bluing, one of the most elegant and attractive is a process often referred to as Silver Nitride. A receiver is said to be Silver Nitrided.

But what is a Silver Nitride finish? The answer depends. It varies somewhat between different manufacturers. The general effect is that receiver has the look of un-blued metal. Un-blued steel would be a disaster as it would be prone to rust and corrosion This would not be acceptable for a fine firearm like a Browning. Browning uses a highly engineered solution for giving the steel the protection it needs with the "silver" or "gray" look you want.

The receiver finish for Browning firearms will be indicated in the Specifications chart at the bottom of the product page.

What is Salt Bath Ferritic Nitrocarburizing?

Browning shotguns with a "Silver Nitride" receiver utilize a proprietary process that is known among those who create metal finishes as salt bath ferritic nitrocarburizing. Over and unders made at our Miroku factory use a product with a trade name of Tufftride. The process leaves the receiver and other steel components with a bright, silver color while at the same time improving the finish and surface integrity in three ways:

Greatly improving scuffing resistance
Improving fatigue properties
Increasing corrosion resistance.

One major additional benefit is that while the process is improving the finish it induces very little shape distortion during the hardening process. This is very important to a finely fitted Browning over-and-under shotgun.

Getting Technical - Controlled Liquid Ionic Nitriding (CLIN)

A more technical description is provided by the company that owns the process and can be helpful if you are looking for more a more detailed answer. Controlled Liquid Ionic Nitriding (CLIN) is the family name of different nitriding/nitrocarburizing processes which are well known under various tradenames. CLIN (controlled liquid ionic nitriding) treatment can be used in a temperature range from 480 °C to 630 °C and enriches the surface of ferrous materials with nitrogen as well as small amounts of carbon. CLIN salt bath nitriding greatly enhances properties like:

Wear resistance
Fatigue strength
Corrosion protection
Cosmetic appeal

Compared to coating or heat treatment processes CLIN salt bath nitriding offers numerous advantages.

A description is also found on Wikipedia under Ferritic nitrocarburizing.