THE SHOP

Performance & Hotrod Business - July '15

Issue link: http://read.uberflip.com/i/524418

Contents of this Issue

Navigation

Page 66 of 101

July 2015 n PRECISION ENGINE n 7 clockwise relative to the hole entry until you begin to feel noticeable resistance. At that time, back the tap out a little bit and then resume cutting threads. Occasionally, it may be wise to remove the tap com- pletely and blow out any chips from the hole. Clean the tap threads with a stiff brush, (an old toothbrush works fine), and resume tapping. If you're cutting threads in a blind hole, before you begin to cut threads, first care- fully measure the hole depth, and place a reference mark on the tap to indicate when the tap is approaching the hole bottom. The mark can be a magic-marker mark, or you can wrap a piece of masking tape to the tap at the depth mark. If you're using a bottoming-style tap, you'll usually be able to cut threads within about 1/8-inch from the hole bottom, (depending on hole and tap diameter). Don't continue to turn the tap into the hole once the tap bottoms out, since this will only result in thread damage, or pos- sible seizing or failure of the tap. Once the hole has been threaded, run a rifle brush through the threads, (help- ing it along with a few turns), followed by blowing the hole clean with compressed air. Always wear eye protection whenever applying compressed air into any hole. Note: If by chance you blast or glass- bead the workpiece prior to threading, make sure that the hole is free of any blast media. By the same token, if you blast the piece after the hole has been tapped, make sure that you clean the threads of blast media before painting, plating or inserting a bolt. Abrasive blasting media can really mess up your threads if they're forced into the threads with a tap or bolt. Keep them clean. Using a Die A threading die will allow you to create threads on a male workpiece. Using a die Thread inserts, (a helical insert shown here), require the use of a special driver tool. Various designs are available depending on the brand. The insert threads onto the driver and is engaged at the insert's bottom tang. The tang exists strictly for installation purposes, and is broken loose and removed once the insert has been fully installed. A helically wound thread insert must be installed slightly below flush with the top surface. If the upper end of the wound insert is too close or above the surface, the upper end of the winding may pop out, which creates a host of problems including poor retention, preventing bolt entry and obstructing the mating surface. • Pistons & Rods • Phone: 949-567-9000 • CP-Carrillo.com • No longer does low cost mean low quality. The Bullet Series Pistons and Rods are manufactured by CP-Carrillo from locally sourced materials, made in the USA. Now available for a wide range of makes and models. • Centralized manufacturing cells • Application specific forgings and hardware • Larger production runs • Available off the shelf • Same machining and tooling as the CP-Carrillo lines of products • Rigorous quality control • ISO 9001 certified

Articles in this issue

Links on this page

view archives of THE SHOP - Performance & Hotrod Business - July '15