Identify these Taps

[4435]

These are some my grandfather had he has been gone some 64 years so can't ask him. Dad gone 27 years can't ask him. The one with the square drive is marked 5/8 3/4-12 it is the only one with any legible mark. These are tapered enough you can start with a full size smaller from tip to butt. (IE 3/8 to 7/16) If they are whitworth I can't imagine what they could have been used for. Gramps was a Case tractor, thresher, combine kind of guy. Tom

 

[tractorguy2]

They look like taps to cold weld a casting crack. My dad use to
cold weld WD9 heads.

 

[Spook]

(quoted from post at 21:59:23 02/06/17) These are some my grandfather had he has been gone some 64 years so can't ask him. Dad gone 27 years can't ask him. The one with the square drive is marked 5/8 3/4-12 it is the only one with any legible mark. These are tapered enough you can start with a full size smaller from tip to butt. (IE 3/8 to 7/16) If they are whitworth I can't imagine what they could have been used for. Gramps was a Case tractor, thresher, combine kind of guy. Tom

I think, the one on the left is a 4 flute tap, pretty common.
The rest I don't think are taps, but thread chasers, or repair devices, they are to clean out existing tapped holes that are buggered up. That's why they have rectangular tangs, rather than square. The rectangular ones are made for cleaning out holes, using a open end or adjustable wrench to turn them.

 

[Bob]

(quoted from post at 23:59:23 02/06/17) These are some my grandfather had he has been gone some 64 years so can't ask him. Dad gone 27 years can't ask him. The one with the square drive is marked 5/8 3/4-12 it is the only one with any legible mark. These are tapered enough you can start with a full size smaller from tip to butt. (IE 3/8 to 7/16) If they are whitworth I can't imagine what they could have been used for. Gramps was a Case tractor, thresher, combine kind of guy. Tom

POSSIBLY some sort of "bo.lermaker's taps", used for threading holes in steam boilers for inserting staybolts or attaching accessories.

http://www.practicalmachinist.com/vb/archive/index.php/t-190439.html

http://www.practicalmachinist.com/vb/general/boiler-thread-angle-210591/

http://www.rypn.org/forums/viewtopic.php?f=2&t=37555

 

[4435]

Bob, That boiler information sounds very plausible. In addition He may have picked them local here in Parsons as there was a huge Katy RR installation here. Thanks Tom

 

[HALGETIT]

Bicycle petal taps. tapered threads to lock petal in the threaded holes on the crank.

 

[HALGETIT]

should have been pedal not petal.

 

[Janicholson]

Pipe taps with a common TPI the set could be used with tapered pipe male threads and make a liquid tight joint. Though not
today's TPI, it would work well, and make allowance for abnormal male threads by adjusting the depth of threading.
Note: Bike pedals are common fine threads (usually in inch spec) left and right hand, not tapered.