Wartime threaded fastener finishes British aircraft - in general?

Read the forum code of contact

Member for

11 years 1 month

Posts: 60

For an Airspeed ww2 aircraft what's the likely finish of steel nuts bolts in general structural areas? Is it almost always Silver Cadmium ? Plain steel?

Appreciate this is a big subject with many different specs by different manufacturers - but without digging too deep just after a general principal.

I have seen some evidence of small BA fasteners on instrument panels having black paint on dome head bolts -also seen this in new old stock supplies but bigger fasteners I'm less sure of?

Original post
Profile picture for user NewQldSpitty

Member for

2 years 2 months

Posts: 69

Silver Cad for generally everything or black Cad for instrument screws.

Profile picture for user Nicko

Member for

9 years 2 months

Posts: 226

It seems that some nuts and bolts (eg, AS1242 HTS bolts) are gold Cad. Not sure if this finish was present during WW2 or if this came later.

Some will be brass - near compasses. These are tinned (but not always?). If you don't have a schedule of spares to tell you which ones are brass, I can say that all loose nuts and bolts securing the bits to the blind flying panels on the Vampire are brass (or stainless steel in the case of the nuts, washers and stud fittings for the isolator mounts). Not sure about the arrangement with the standby compass. I have tried interpreting AP.970 (engineering requirements) on this topic, but to me it is a little ambiguous.

Member for

1 year 10 months

Posts: 170

Hi Nicko. Are you sure the items aren’t zinc plated? 

Profile picture for user Nicko

Member for

9 years 2 months

Posts: 226

Going off the Brown Brothers catalogue:

image-20211217112301-1

Profile picture for user Nicko

Member for

9 years 2 months

Posts: 226

AP.1086 Section 28S refers to brass screws as 'tin-coated'.