Need some info on sizing.

[GrantH]

Hey guys, i've searched a bit for this and can't find a direct answer.

I need the diameter needed for threading 10x1.0 dies, and the diameter needed for threading 1/2x28 threads. If anyone can please help me out here, i'd be very grateful.

10mm - 1 = 9mm needed for threading?

As for the 1/2 x28...how do you figure that out?

 

[The Penguin]

google "tap die chart"

here's an example:

Drill Chart

 

[GrantH]

got it! between .4924 and .4989

 

[GrantH]

got it! between .4924 and .4989 for the die and .4562 for the tap. Both of these for the 1/2 x 28 tpi.

Corrected.

 

[mredburn]

The metric rule of thumb i use is subtract .2mm from the working diameter for the die.
10mm-.2mm =9.8mm adjust from there. For the tap the hole will be the working diameter minus the pitch. 10mm x1 means subtract 1mm so 9mm or 10 x .75 subtract .75mm or 9.25mm hole. I usually drill my holes slightly larger for ease in cutting and fit. the 9.25 I will drill closer to but not larger than 9.4mm

 

[watch_art]

I use an open end box wrench while I turn. WHen the wrench moves freely over the tenon, with JUUUUUUST a hint of light between the tenon and wrench, I thread it. Depending on the material, I might turn off a bit more. For PR it's better to err on the side of taking too much off. But be careful. Take TOO much off and you won't have enough left to thread! :biggrin: