When you think of high hazard industries, where people can easily be injured in their work environment—what comes to mind first? According to the Bureau of Labor Statistics (BLS), construction, mining, transportation and manufacturing rank top in the list.
The manufacturing industry in particular, often involves the handling of complex machinery, large and heavy parts, sharp blades, and the moving of components at high speeds, all of which contribute to the high risk of work injuries. According to the BLS, approximately 40 percent of workplace injuries in manufacturing are associated with the contact of objects and is the number one cause of injuries.
Bird Nesting Problems
While producing fuel tanks in SAE 1020 steel, where holes are required to be threaded, tractor manufacturer Valtra was encountering tap breakage due to the formation of bird nesting, in which cut chips ejected during operation would wrap around the workpiece, quickly disrupting the tool path. These fuel tanks are made for tractors of small, medium and large sizes. The company has been producing these parts for more than 20 years. There are 35 blind holes at a depth of 34 mm per workpiece with a tolerance requirement of 6 HX.
A cut tap was previously used to thread the company's
fuel tanks in SAE 1020 steel and was troubled by
bird nesting problems.
The company was using a HSSE M16 DIN 376 TiCN coated spiral fluted tap with a 45-degree helix to thread the part with welding points near the threads. When the problem arose, the machine would have to be stopped, which caused costly production delays. Moreover, the malleable material of the workpiece and the formation of the spiral chip were causing a safety risk to its employees as the problem required manual removal of the tool and cut chips.
Finding A Solution
The fuel tanks require the threading of 35 blind holes per part
at a depth of 34 mm in SAE 1020 steel.
Instead of using a spiral fluted tap, OSG proposed the HSS-Co M16 DIN 376 S-XPF forming tap with V coating. Initially, Valtra was hesitant, but the forming tap was able to thread external hardened weld points and hardened materials due to a low-torque design to facilitate longer life at faster speeds.
Valtra applications engineer Jeferson Barreto said the technical support helped to discover a new effective solution in their manufacturing process. He added that “this partnership had allowed us to improve and guarantee a more profitable and safe process”.
APMEN Online Exclusive, September 2017