Shop Floor Talk  

Go Back   Shop Floor Talk > Welding and Metalworking Forums > Machining

SFT Search:   
Reply
 
Thread Tools Display Modes
  #21  
Old 01-28-2014, 12:42 AM
coleasterling coleasterling is offline
Senior Member
 
Join Date: Jun 2007
Location: Post and College Station, Tx
Posts: 536
Default

Dub,

Ever thought of using a cordless drill? Set the clutch low enough to not over-torque the tap and be careful of getting it straight and it'll work great. I do this all the time with some Snap On 1/4" and 3/8" drive square tap adapters. They let the tap pivot a little so that once the tap is in, you have to work to put a bending moment on it. I've seen eight piece import sets for around $35 on the interwebs.

Last edited by coleasterling; 01-28-2014 at 02:44 AM.
Reply With Quote
  #22  
Old 01-28-2014, 12:54 AM
LKeithR's Avatar
LKeithR LKeithR is offline
Hey...wait...is there a prize?
 
Join Date: Aug 2011
Location: Langley, B.C.
Posts: 5,638
Default

Quote:
Originally Posted by PixMan View Post
Actually, a "gun tap" is a common name for a spiral point tap. It's a spiral flute tap which will carry chip up the flutes and out of the hole in a similar manner to a drill.
Spiral point taps work much better than spiral flutes. They push the chips ahead of the tap and away from the cut--best used on through holes but they'll work OK on blind holes if you can make them a little deeper. Spiral flute taps are more prone to breakage because they have more tendency to plug up...
__________________
Keith

Measure twice and cut once...or...wait, was that the other way around?
Reply With Quote
  #23  
Old 01-28-2014, 09:41 AM
dubby's Avatar
dubby dubby is offline
Twice the size--half the man
 
Join Date: Apr 2006
Location: Lubbock, TX
Posts: 10,030
Default

Quote:
Originally Posted by coleasterling View Post
Dub,

Ever thought of using a cordless drill? Set the clutch low enough to not over-torque the tap and be careful of getting it straight and it'll work great. I do this all the time with some Snap On 1/4" and 3/8" drive square tap adapters. They let the tap pivot a little so that once the tap is in, you have to work to put a bending moment on it. I've seen eight piece import sets for around $35 on the interwebs.
Yup. We did that for a while and it actually works pretty well in the hands of the right operator. Irwin has a decent little tap holder with the square drive, and we've run it with both a cordless drill and an air ratchet. The taps usually hold up well enough that it's no big deal, but with those type of setups you can actually get the tap way off center even if you think you've got it started right. The lack of 'feel' in your hands really does make a big difference on tasks like this and often we don't think about that.

Now, threading is a whole 'nother story. For each one of these little rounds that I tap a hole in, I thread a 5/16 shaft on two ends to accept them. One goes into the round, another goes into a factory-made knob. That cordless drill is the way to go there. I put a die into the bench vise, put the rod into the cordless drill chuck, dip the other end into cutting fluid, and thread that little bugger with a quickness. Pull it out, flip it around, do the other end.
Attached Thumbnails
Click image for larger version

Name:	805180_300.jpg
Views:	93
Size:	12.8 KB
ID:	113091  
__________________
I've always had more time than money.

Wade's Custom Kydex
Reply With Quote
  #24  
Old 01-28-2014, 11:51 AM
PixMan PixMan is offline
Senior Member
 
Join Date: Jul 2011
Location: Central MA
Posts: 431
Default

Quote:
Originally Posted by LKeithR View Post
Spiral point taps work much better than spiral flutes. They push the chips ahead of the tap and away from the cut--best used on through holes but they'll work OK on blind holes if you can make them a little deeper. Spiral flute taps are more prone to breakage because they have more tendency to plug up...
Yes, of course I know this because I'm a master machinist with nearly 40 years in the business.

Most commonly the spiral flute taps (made for blind holes) will break because someone using them thought to stop and reverse it to break the chip while tapping. OK for a hand tap, NOT ok for spiral flute taps that are supposed to go to full depth on one shot. If you do stop and reverse the tap to break chips halfway down the hole, expect trouble.
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Web Search:

All times are GMT -5. The time now is 03:31 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2022, vBulletin Solutions Inc.