Warbird Information Exchange

I have been acquiring WWII CAD I ("White" or "Silver" Cadmium) bolts for an upcoming restoration. My goal is 100% authenticity to the WWII era so I wanted to get the WIX brain trusts opinion. The following is a list of all the different head markings that I have encountered on CAD I bolts. Please confirm that they are WWII era, comment on their markings/manufacturers/origins etc., and let me know if there are any other head markings that you have encountered on WWII aircraft. If any of these are not WWII let me know. I hope this thread becomes a discussion on appropriate era hardware. Please feel free to upload photos of your hardware!

1. AERO

2. AERO SUPPLY

3. Air Associates (Indented lettering)

4. ALS/LSA/SAL

5. AN (Indented lettering)

6. AN (raised lettering)

7. AN (raised lettering with circled x)

8. ASCO

9. B

10. CP

11. CPP

12. DAA

13. E

14. LSC

15. LSC FL4

16. LSN FL4

17. SNM

18. SNM

19. SNMX

20. RM

21. Rockford Sp. Co.

22. Thick X with Hollow Diamond

23. Plain CAD X Mark




Also, I have run across several original CAD I bolts that have been dipped in some sort of Red, Green, or Purple dye (mostly red). What does this signify? I have specifically heard that red meant a certain percentage of a lot was checked (i.e. 1/1000 bolts etc.) and that green meant that all the bolts had been checked. That is why you see red dye on smaller bolts and Green on larger ones. Is this true? I have a 1941 copy of "Magnaflux Aircraft Inspection Manual" by Doane and Thomas and it refers to a "red paste designated as No. 9, which has become available during the past year [1941], and its use is growing rapidly". This is a liquid paste suspended in oil used in the magnaflux testing process, could this be the residual red dye that I see on my bolts? The manual says the paste is to be washed off, but that the rinsing process may leave residual paste. If anyone has any insight into the subject I would be excited to hear it as I want to be 100% original in its application, origin, and use on other hardware items.






Thanks

_________________
Taylor Stevenson

As far as manufacturers head markings on bolts, I am confident I have seen all except 9, 11,12 and 22. fairly certain on 15, 16, 17.

The real problem is I have not paid attention as to which era aircraft I have seen them on. 99% sure unlisted numbers above I have seen on un molested WWII period aircraft and parts.

As far as I know, and remember seeing on older aircraft with batch dyed hardware, the colors and uses seem to be varied among manufacturers.
Most frequently used seems to be orange dye to denote Magnetically inspected hardware (such as used in wing attach, engine mounts...) . This seemed to have been an industry standard. I also recall having seen green dye used in this app. especially on bolts with a "M" (in a half circle) stamped on the head.
Many times I recall seeing where batch dye was used to delineate different lengths of screws or bolts used in an area of assembly where fastener engagement was blind. Example: A part with 2 different screw lengths, such as a fuel tank stress panel, or a part with different length bolts in an application such as bolted attach angles, machined parts or a casting with varied thickness. The different fastener color sped up assembly time, insured that the correct length fastener was in the correct location. It also had the added benefit of insuring a quick and accurate quality control inspection. I have seen use of colored bolts that were matched to a marking (grease pencil, ink stamped arrow... ) on surface of subject part.

It is possible that some of the members more closely involved in manufacturing could enlighten us more as to the old ways.

_________________
Expert:
Ex: Former.
Spurt: A drip under pressure.

Yep, I Agree with my buddy Mike. That's the way I know it to be.
Chuck