No5 bayonet/knife "conversion"

[Flying10uk]

I did have a look in Graham Priest's book after posting the pictures and it does mention the 3rd hole. It goes on to suggest that the purpose of this hole is to "lighten" the blade which doesn't seem likely to me because it's such a tiny amount of metal that is removed by the presence of the hole. I did wonder, myself, if it was something similar to what Jim suggests in Post 19, an indexing hole, although I was thinking more of a hole to fix the blade to a jig during machining. There are several little indents in the blade which could be hardness test indents or simply areas of corrosion/defects in the surface of the metal.

[browningautorifle]

Rockwell testing uses a diamond shaped striker.

Yes, my Platoon Commander had an FN back in about 1982 that had Rockwell marks on it so I'm familiar...like they'd chosen his to test for quality.

the purpose of this hole is to "lighten" the blade which doesn't seem likely to me because it's such a tiny amount of metal that is removed by the presence of the hole.

Yes, but if you look at the amount of metal gathered over the protracted amount of 5000 or 10,000 blades it's not just lightening but metal reclamation. You can take that metal and put it towards the project and save so many pence over the period and enhance profits... It's an old theory really, seen many times before. They would need a standardizing hole though, indexing for the accuracy of the machines.

[Peter Laidler]

The REAL question here, now that we have seen the photos in thread 18 is this. Has anyone got a stripped or semi stripped No7 bayonet. And if so, could the short remains of the No9 tang end make it useable to repair a No7 with a knackered blade. From memory I am minded to suggest that it COULD. Simply un-rivet the broken blade bit on defective No7, , take off the No5 crosspiece (probably broken anyway....?), shape No9 blade to suit, drill and re-rivet.

Just thinking on my feet........

[Flying10uk]

I do have a stripped No7 bayonet but won't have time to take pictures until next week. Just having a quick look the No9 blade, it looks slightly too short by about 1/4" to do what you say, Peter, unless a shortened No7 bayonet is acceptable. Will post pictures next week.

[browningautorifle]

a shortened No7 bayonet

By probably not much? You'd move the tang forward a quarter inch? An eighth?

[bigduke6]

Flying10,

Regarding post 1, To get it back to a No5 doesn't take too much, here is a link of one I did some time back may give others a few pointers.

https://www.milsurps.com/showthread.php?t=40522

[desperatedan]

I recently purchased this No5 bayonet at a good price because it has a good blade but unfortunately it is also missing it's catch button and has a broken muzzle ring. It was sold to me as a knife "converted" from a No5 bayonet and I thought that a good No5 bayonet could be made from it.

About 2/3 years ago I picked up No.5 that was missing it's catch and managed to find some new make No 5 parts in stock with Jeremy Tenniswood in Colchester at a decent price. Might be worth dropping him a line to see if he still has some available if your don't fancy making your own.

[old-smithy]

Makes sense. (As I'm sure you know) Rockwell testing uses a diamond shaped striker.

a Diamond indentor is a Vickers test, the typical Rockwell is a Ball indentor, Rockwell scale - Wikipedia

[browningautorifle]

a Diamond indentor is a Vickers test

So...the FN C1A1 I observed, CDN issue, would be the Vickers test? Would that make sense? A sharp point like a prick punch...

[Peter Laidler]

A ball was an old 50's IZOD test too.