View Full Version : Makeing Taps, sharpening old ones
07-18-2001, 09:49 AM
I make a plug tap, since I din't have one for 5/8-18 nc. I used a chunk of shaft from a car strut ('94 ford tempo) that I soffened up by letting it cool from a red heat in Al. foil. I made it 8thou over size and stepped off a slight taper on the starting end (very rough). Then I just cut threads as usual. I cut the flutes in my shapper, just a rough hand index. I then quenched from a soft red heat into water. The tap worked well for three holes in steel (all I realy needed) but it lit a fire in me to do a better job. Any advice on material, temper, standards, and what is the dimmensions of a 3 tap set for blind holes? I think it would have worked better if I had made two taps to do the job and not asked one to do the job. I just guessed as to the procedure to make a tap if I am way off base let me know. Thanks Vincent Phelps
Darn, a true believer! Congrats on the tap, more than most would do!
If you are going to do this thing, a good place to start would be Lindsey Publications:
I might start with "Modern Toolmaking Methods" from about 1915. Some of those boys back then are still teaching me!
Get the catalog!
07-20-2001, 07:06 PM
Try Cumberland die supply in Nashville TN I am pretty certin they carry high speed steel in short lengths, you can also use something like oil hardening stock which is readily available from catalog supply houses. The tool steels will get much harder than what you used for your tap. You deserve a pat on the back for making the attempt.
07-21-2001, 07:04 AM
Thanks for the kudos, hope I don't disapoint you by saying I have a set of taps and dies on the way.
I did a postmortom and realized that I my method failed to include any clearance behind the cutting points, and the failure occured on the one time I used it without lube. If I have to use the thing again I will touch it up, and only use it to bottom threads that have already been started.
I get the Lyndsay cat and will get the book. But will start new topic on Machinery's Handbook. Thanks Vince