Straw parts

[Kyrie]

Originally Posted by k98mike

I think Lugers with straw small parts are more attractive, why was it done? The straw finish is supposedly less effective than standard bluing; Did they not know? Was it just considered more attractive?

There is a basic misunderstanding here. Straw (and fire blue) colors are not a finish, are not applied as a coating, and are not primarily intended to produce corrosion resistance.

The yellow and blue colors on small parts are by-products of the heat treatment of those small parts to attain a specific hardness to reduce abrasive wear without inducing brittleness.

Here is a link to a document that details that heat treatment process (historically called fire, or flame, heat treatment), and the temperatures at which specific colors appear (each color denoting a specific range of hardness):

http://navybmr.com/study%20material/...14250A_ch2.pdf

This heat treatment produced hardness has, as secondary and incidental effects, the production of attractive surface color and a very limited increase in resistance to surface corrosion. But this color and small increase in resistance to surface oxidation is just a by-product of the heat treatment done to reduce part wear due to abrasion.