Like many machine shops, one of the world's leading producers of custom-engineered industrial mixing equipment for a wide range of materials-including mining, chemical, wastewater treatment, pharmaceuticals and food-experienced issues with a tapping operation. They were breaking taps 40-50% of the time in a new product design. Synchronizing the threading and reversal is notoriously difficult, especially in a part that is not particularly rigid.
The blind hole in 316 stainless steel is the female end for a threaded adjusting bolt. The 5/8-11 tap would break once it reached the bottom of the hole at about 3x diameter. Every time, they took the part to the EDM machine, burned out the broken part and then manually tapped the hole. It was considered a standard part, but by nature of the company's custom work, a standard part means a few hundred a year-high stakes to say the least. The break rate, the hour to clear the tap and the scrapped material was not sustainable.
It was not until an operator called the tooling coordinator's (a relatively new position at the company) attention to the issue that a concerted effort was made to find a solution. "The background thinking was if we can find a solution for this difficult application, it could end up helping us with others moving forward," the tooling coordinator said.
They tried several different taps and tap holder manufacturers, but still had the same issue of breaking the tap in the application. It was not until their tooling supplier suggested trying the BIG KAISER MEGA Synchro that they realized they were on to something.
"The tap breaking problem was eliminated," the tooling coordinator said. "We also saw improved performance, tapping at 50 SFM where we used to run at 25 SFM. This speed is faster than the tap manufacturer recommended but we have seen no issues. This is the first time we have ever been able to tap into a blind hole at 3x diameter faster than the manufacturer recommends. If you take a magnifying loupe and look into the threaded hole, instead of it looking like it was cut or torn, it almost looks like it was thread milled."
Having the ability to use the coolant-through feature of the tap holder also allowed for continuous tapping without adding a lubricant during the tapping operation. That also helps save time and maintain coolant conditions. This is especially important on newer machines with safety features that lose the cycle when the door is opened.
The tooling coordinator's hopes of migrating the holder to other work came to fruition. They started trying the MEGA Synchro in different applications at different work centers, across a mix of materials that included cast iron, steel, Hastelloy, titanium and other super alloys at lengths up to 5x diameter.
Other than an operator or programming error, the shop has not had to replace any of the MEGA Synchro holders or the parts for them, including the first one they bought in 2012. Overall, the results have been fewer tap purchases, better results and eliminating the difficulties and delay of removing broken taps.
They are now gradually implementing the MEGA Synchro on all of their CNC mills and mill/turn centers-from new purchases to legacy machines up to 30 years old. Operators request MEGA Synchro whenever another brand of tap holder wears out.
For more information contact:
BIG KAISER Precision Tooling Inc.
2600 Huntington Blvd.
Hoffman Estates, IL 60192
888-TOOL-PRO / 224-770-2999
bigkaiser@us.bigkaiser.com
www.bigkaiser.com