Am i going to break this tap if I....

[Makintrax73]

I bought a "lot" of metrology tools cheap. Came with a Noga arm NO Base. My current base the arm bolt is 8mm-1.25. The Noga arm is 10-32.

I have zero metric dies, and my lathe is imperial, otherwise I'd use brass. Considering buying the cheapest low grade 8mm bolt at the hardware store, drilling the center in a collet chuck, and tapping 10-32 through the middle to make an adapter.

But can you tap bolt steel with a HSS tap, or am I going to end up regretting this? I know cutting bolts with hss lathe bits is sketchy...

 

[markba633csi]

Low grade bolts can be easily cut, drilled, and tapped- even up into the mid-grades
Use a good USA tap

 

[Makintrax73]

Thanks Mark since that's my cheapest option I'm going to give it a go

 

[MrWhoopee]

I'm going to suggest that the 10-32 is actually M5 (x.8). They are VERY close, but M5 is a few thousandths bigger. You can screw a 10-32 into an M5 tapped hole, but frequently not the other way around.

 

[pontiac428]

I'm going to suggest that the 10-32 is actually M5 (x.8). They are VERY close, but M5 is a few thousandths bigger. You can screw a 10-32 into an M5 tapped hole, but frequently not the other way around.

Yep, even Boeing has made that mistake!

 

[darkzero]

Are you sure that's 10-32 on the Noga? I don't think it is. All the Noga stuff I have has metric threads & Noga is made in Israel. Looks like a NF size arm which should be M5 thread.

NF - M5
DG & MG - M8

 

[darkzero]

BTW, I've made adapters a few times for mag bases. But in my cases they were all for a thread larger than the base. The last two I made were for lamps & I just used aluminum.

If you feel like you might break the tap, you can buy M8 to M5 adapters. Never tried em myself though.

https://www.amazon.com/PATIKIL-Adapters-Repairing-Conversion-Stainless/dp/B0CH9FYXJB/

https://www.amazon.com/Reducing-LUORNG-0-47inch-Stainless-Accessory/dp/B0CCNSJ44J/

 

[Makintrax73]

Thank you guys. You're correct, this Noga base is 5mm-.8 ..... I guess it helps if you actually measure instead of eyeball it.

In my defense a 32 pitch thread gauge seems to drop right in. The clue I missed is the threads measure about .005" bigger than 10-32. Looks like I'll be buying a 5mm tap.

 

[ChazzC]

Thank you guys. You're correct, this Noga base is 5mm-.8 ..... I guess it helps if you actually measure instead of eyeball it.

In my defense a 32 pitch thread gauge seems to drop right in. The clue I missed is the threads measure about .005" bigger than 10-32. Looks like I'll be buying a 5mm tap.

One handy thing about Metric fasteners that are close to Imperial ones (M5 |10-32, M6 |1/4-20| M8 |5/16-18): you can mix & match washers to get closer fits and different OD's & thicknesses than are available within the stock Metric/Imperial sizes.

 

[rwm]

Yep, even Boeing has made that mistake!

Was that the issue with the door plug or something else? I did not read that?