Mounting bolts for H&F 9x20 lathe

[Stustoys]

I thought 7/16in is 11mm, oh well

It is pretty much. But the thread depth is more than 0.5mm

[chris...]

I'll buy one and find out

[mav_walrus]

chris

The bolts are M12 1.75 pitch.

You need to pack and then bolt your cabinet to the floor. I used angle bolted to the sides of the cabinet then dynabolted to the floor as the holes underneath the cabinet are too hard to get to.

When the cabinet is absolutely rock steady, bolt the headstock end using a bit of strap ... washers will deform.

chuck a bit of rod and mount a dial test indicator at the tailstock end. Bolt down the tailstock end until you see movement and then back off a fraction. If thats not tight enough pack the headstock up with a sheet of paper and then repeat.

Attachment 157003

Mav

[Grahame Collins]

Chris,
Stu is talking about the root diameter of the bolt.I believe you are talking about the OD .So you are not talking about the same thing OK!.

The measurement of the ID of the nut welded to the mount is the root diameter of the bolt not the ID.

To find the true od of the bolt required you will probaby need to have acess to a bolt data table.
I would hazard a guess and say you probably need coarse metric not fine.

A M12 coarse pitch bolt runs at 9.83mm root diameter according to my reference.
Grahame

[Stustoys]

Grahame
I'm not so sure we arent talking about the same thing.

chris
If you tell us the inside dia of the nut someone will take a guess. If its a metric nut then the guess will most likely be right.

The inside thread is a bit over 10mm

The root Dia of a M12 bolt is 9.8ishmm(depending on the ref).
The root Dia of a M12 nut is 10.1ishmm(depending on the ref)

"The measurement of the ID of the nut welded to the mount is the root diameter of the bolt not the ID."<<Is this second ID meant to read OD?
Stuart

[chris...]

I'm talking about the kinda of thing a newbie with no idea or formal training would talk about, I've never heard about root diameter or what it means or why its used. I just literally measured the inside nut diameter, the distance across the inside of the nut from inside thread to thread

[Stustoys]

Don't mind us chris.
Based on "distance across the inside of the nut from inside thread to thread " being "a bit over 10mm", I still believe the bolt you are after is M12.

Don't forget to work out how long you want it as depending where you go the lenghts come in 5mm steps. Also if a hex head or a capscrew (allen key) would be easier to fit.(looking at Mavs picture a hew head would be best)

p.s. Mav that bolt looks loose?

Stuart

[Grahame Collins]

Grahame
I'm not so sure we arent talking about the same thing.



The root Dia of a M12 bolt is 9.8ishmm(depending on the ref).
The root Dia of a M12 nut is 10.1ishmm(depending on the ref)

"The measurement of the ID of the nut welded to the mount is the root diameter of the bolt not the ID."<<Is this second ID meant to read OD?
Stuart

You are of course correct stu,I should't do2 things at a time .I invariably get them both wrong.
Grahame

[chris...]

M12 I shall try
The pic Mav showed is the same as what I have

[mav_walrus]

Stuart

The bolt is not loose ... but the washer is deformed from bolting it down without the bit of 6mm strap it's sitting on. Should have straightened it first but I thought bolt would pull it down. (Mav's spring washer)

Mav