Chasing threaded holes for reassembly - faster method? Tool?

[garbs]

Hello Everyone

Where I work we refurb large machinery for pulp and paper industry.

Before reassembly we chase(retap) thread holes to ensure no issues during assembly. Many of the parts and fasteners are stainless and we dont want to risk cross threading, or pickup from the bolts.

Currently we have millwrights doing this (small shop), is there any tool or method that could accelerate this? Any ideas are appreciated.

Thank you.

[CCR5600Design]

What size are the fasteners?


Ron

[Goingforsound]

Cordless drill with a spring chuck. It have a clutch built in so you can go full speed in the hole and it stops on the bottom

[Goingforsound]

Here's a little one...

http://www.mcmaster.com/#power-drill...hments/=izn1na

[PinkertonD]

You could get some taps modified by grinding the first say, 3/8" to just under the root diameter and a slightly pointy tip for lead into the hole. Using a power drill, (battery corded etc) this would ensure alignment before engagement. Providing the application pressure was not too great (enthusiastic worker) the tap would probably pick up the thread start OK.

I would not use a spiral point tap as they are very good at starting a thread. You want the tap to resist cutting into new metal and instead find the old thread start.