esantoro Report post Posted December 20, 2007 In a couple of days I'll be getting thread wipers from Ferdco for my lube pot. I can handle the drilling required, but I have never tapped a hole before. I imagine tapping a hole is the same as threading a hole. Do I just run down to Lowes or Home Depot and pick up a tapping bit of the required size, chuck it up and drill, or is this a hand operated procedure. I'm really looking forward to using the lube pot full time. Thanks for the help. Ed Quote Share this post Link to post Share on other sites
Regis Report post Posted December 20, 2007 It is a hand operation. If you haven't done this before, it is very important that the tap is perpendicular (90 Degrees) left to right and front to back. Remember pipe threads are different than bolt threads so be sure you get the correct thread as well as diameter. Use some kind of oil and turn the tap about a half and back up a quarter. Keep doing that until you complete. Typically the tap is slightly smaller at end so you have to go a little farther than just barely through. When you buy the tap, be sure to check the exact size drill bit to use. Close or eyeballing is not good enough. Be sure to clamp in vice to drill because any wobble will mess up your threading. So, now I've told you all the mistakes I've made tapping. Quote Share this post Link to post Share on other sites
Jordan Report post Posted December 20, 2007 Go slow use your drill press and a vise to hold everything level and at right angles use cutting oil and there is a chart that tells what size drill bit for what size tap also the tap has to match the diameter and thread pitch of the part, then the actual threading is done by hand again, go slow and keep everything angled properly It seems harder in writing than it actually is. also you get to choose metric or standard plus all the stuff regis mentioned. Jordan Quote Share this post Link to post Share on other sites
wolvenstien Report post Posted December 20, 2007 For very thin stuff, I use my tapping tool: http://www.homedepot.com/webapp/wcs/stores...uctId=100061497 For thicker stuff, if I dont already have the right size tap and bit, I pick up one of these, but you would have to buy the tap handle separately like the one in the combo below: http://www.homedepot.com/webapp/wcs/stores...ocStoreNum=1769 And here is a set of taps and bits... but the drill bits are all purpose... not specifically for metal.... http://www.homedepot.com/webapp/wcs/stores...uctId=100081358 Take the screws/fasteners with you and get them to put it on a gage to match it up with the tap you need. Quote Share this post Link to post Share on other sites
esantoro Report post Posted December 20, 2007 This is such great help. guys. Thanks. Ferdco is also writing up all the specs I need to do the job right. Just in case I screw up, does anyone know where I can get these cast iron lube pots cheap? I could always plug the messed-up hole and drill another. By the way, the cast iron lube pot i'll be drilling through and tapping is 7.5 mm thick. In measuring it, I just noticed another thing. the current existing thread exit hole in the pot is already threaded. I'll call Ferdco and ask if this predrilled and threaded hole is already the right size, which would be very nice. Ed Quote Share this post Link to post Share on other sites
esantoro Report post Posted December 20, 2007 just got off the phone with Ferdco. The drill bit and tap specs needed are as follows: drill bit 25/64 tap 7/16-20 I'm off to the hardware store, as I have neither of these in my toolbox. Thanks again for the help, ed Quote Share this post Link to post Share on other sites
wolvenstien Report post Posted December 20, 2007 dems some big bolts.... Quote Share this post Link to post Share on other sites
esantoro Report post Posted December 20, 2007 yeah. The original threaded hole is about three mm in diameter. out of luck there. Quote Share this post Link to post Share on other sites
steveb Report post Posted December 20, 2007 with big holes - youve got to go slow and not let the tap bind up - work it in, then work it out - ahead a 1/4, back a 1/2 - go slow and use lots of tap lube or 50wt motor oil and keep the chips out of the area as you move the tap ahead. when you drill your hole, make sure you use a sharp bit and lube it well - 2 hands on the drill getting all of your surfaces perpendicular/straight helps alot - but this will be tough to do in a hand held situaiton good luck Quote Share this post Link to post Share on other sites