taper pin reamers

[jwallace]

I recently bought an entire estate table full of 40s 50s
machinist tools, more than I will ever use
cost $50.00. In the lot were a number of new
taper pin reamers from small to about half an inch
someone tell what the use of these is I am not
familiar with there intended use.

 

[b.lindsey]

Generally they are used to ream the hole for a taper pin used as a connection between mating parts. The pin itself is similar to a dowel pin though obviously tapered. I suppose it gave a good enough connection with the advantage that it could be pressed out easier than a straight dowel pin, or spring pin. Back when I was doing mold work, I used them for sprue holes which tapered from smallest end at the injection nozzle to the largest end in the mold cavity. This taper allowed the plastic sprue to release from the mold and come out with the molded parts.

Bill

 

[Philjoe5]

To add to what Bill said, they have an additional advantage over straight or spring pins. If the pinned parts are ever disassembled, they can only be reassembled in the same orientation which can at times be useful.

Cheers,
Phil

 

[radfordc]

Tapered pins also allow for absolutely slop free fits. If you drill a straight hole and insert a bolt you still have some small amount of clearance. With a tapered pin the pin pulls into the tapered hole and forms a zero clearance fit.

Charlie

 

[mklotz]

With straight pins, both pieces must be perfectly aligned to insert the pins. Tapered pins will draw the pieces into alignment as they are inserted. This can be a considerable advantage if the parts are awkwardly located.

Totally unrelated... Taper pins are used to model Morse taper fittings on the PMR machine tool models - metal lathe, wood lathe, drill press and milling machine.

 

[agr]

Could they not also be used to produce tapered plug valves?

I'm not sure of the required angles, etc of taper pins vs valves, but I do know I inherited a small collection of tapered reamers that were used to ream the body of small steam plug valves.

Tony.

 

[Philjoe5]

That's a good point Tony and I hope you get a response. Reason being, I'm considered taper pinning a few joints on my current build. It would be nice to know if I could use them for other things since they aren't cheap. I do have some drain cocks to make.

Cheers,
Phil

 

[Maryak]

Could they not also be used to produce tapered plug valves?

I'm not sure of the required angles, etc of taper pins vs valves, but I do know I inherited a small collection of tapered reamers that were used to ream the body of small steam plug valves.

Tony.

Guys, I don't see why not. For mine the angle is not all that critical it's just a case of a male-female match. I would do a final fit with toothpaste, followed by brasso.

Hope this helps

Best Regards
Bob