Muhle thread pitch mystery Sovlved

[cooncatbob]

Well I received my M5 x .8 D4 tap today and it's virtually identical to a over sized #10-32 H11 tap. The metric tap is a few .001s larger.
So a Gillette head will screw in to a Muhle handle but a Muhle head might not screw into a Gillette handle, a lot of Gillette's have over sized threads.

[ateace]

Bob - what thread size do you use on the Bull Mastiff?

[cooncatbob]

Bob - what thread size do you use on the Bull Mastiff?

I use a #10-32 H7, but if requested I can run the larger metric tap down the hole.
I don't want to indiscriminately use the larger tap on all my handles, some old Gillette's especially Old Types have worn or under under sized threads.

[SepticTank]

Well I received my M5 x .8 D4 tap today and it's virtually identical to a over sized #10-32 H11 tap. The metric tap is a few .001s larger.
So a Gillette head will screw in to a Muhle handle but a Muhle head might not screw into a Gillette handle, a lot of Gillette's have over sized threads.

That would make sense - since Mühle is made/designed in and Germany went metric about a million years ago... I used to send heaps of imperial sized tools over to a friend in Germany who was making a steam engine from scratch from original drawings and the project was all imperial and he simply couldn't get the tools.

[Stubblefield]

Excellent detective work, Bob. I had a feeling that if anyone solved the mystery it would be you.

[cooncatbob]

That would make sense - since Mühle is made/designed in and Germany went metric about a million years ago... I used to send heaps of imperial sized tools over to a friend in Germany who was making a steam engine from scratch from original drawings and the project was all imperial and he simply couldn't get the tools.

This is what had me confused, Merkur heads and handles would interchange with most Gillette's and they ones that didn't I thought was due to the plating.
I work in cabinets and the threads are #8-32 and the Euros are M4.
Well they are close but you can only get about 2 turns before they jam, so I never thought that a metric and a imperial would be interchangeable.