View Full Version : Tap Size?
05-14-2005, 03:35 PM
I'm working on a college design project and I need to drill and tap a hole for a schrader valve core (Bike valve). I measured the major outside diameter of the threads to be .201" and the pitch as 36 TPI. The nearest size I calculated was a 13/64" (.203"). Does anybody know where I can find a tap this size, and what type it would be(SAE, UNF, UNC)?
05-14-2005, 04:09 PM
I just sort of looked around my shop at the different references and could find anything close what you describing in the way of taps.
I check on the KBC tools website and found nothing, Could this be a metric size or a number 6 drill size?
Have you called one of the bike shops in your area?
Here are some places I found on the net:
05-14-2005, 04:10 PM
Original post was wrong. edited by me as to not look like a dumb a55 lol If you figure out the right size try these places. www.jlindustrial.com (http://www.jlindustrial.com) or mcmastercarr online.
[This message has been edited by mochinist (edited 05-14-2005).]
05-14-2005, 04:24 PM
It was discussed here: http://bbs.homeshopmachinist.net//Forum1/HTML/007108.html
Try auto parts store or HVAC supply house, they are common in refrigeration also.
05-14-2005, 08:55 PM
I attempted to make a tap out of some stainless steel I had. What I came up with was barely capable of tapping some aluminum about 1/2" depth. Just about enough to confirm that the schrader core is 36 TPI, and that .201 inches is the right diameter. The schrader valve fit in just about perfect. So I know it isn't metric (if it was it would have a 5.05 mm diameter and a .706 mm thread pitch. I just need to find a tap that size, if anyone happens across a 13/64"-36 tap could they email me? firstname.lastname@example.org.
05-15-2005, 10:40 AM
A quick google suggests 1/8 NPT
05-15-2005, 10:52 AM
You have a #11 screw. Check this out...
I have looked a couple of places and cannot find any other reference to this size thread. May be something specific to the industry. ?????
[This message has been edited by C. Tate (edited 05-15-2005).]
05-15-2005, 11:17 AM
I think you were on the right path when you tried to make the tap. Get yourself some drill rod and do it again. Once you have the tap to your sasisfaction, harden it. You can then tap multiple holes with your custom tool.
If this is for a low pressure application, you could also purchse a valve stem for mag wheels, machine off the parts you don't need and epoxy the valve and its housing in place using JB Weld. Perhaps, the mag wheel schrader could be bolted in place as they are on wheels. You didn't describe the need for this valve in your project so I don't know the requirements of the "box" we're working in. Is screwing this valve in the only solution??
Genuine auto parts houses usually carry Schrader tank valves with 1/8 - NPT on the other end.
Get one of these tubeless truck tire stems (available in many different lengths and for 9.7mm (3/8") or 16mm (5/8") hole size). These need to be inserted from the back side of the hole. If that isn't possible, the 16mm size could be turned and threaded to just about anything you want.