All-purpose A-Tap stops tool breakage in hand tapping process of rolling stock production
Gabriel Fernando Gialorenço | OSG Sulamericana
Rail transport is one of the most sustainable mode of transports available today due to its cost effectiveness, reliability and minimal impact to the environment. Developed to handle both freight and passenger traffic, rail transport demand continues to rise around the world in response to rapid urban expansion and globalization.
Owned by the Hyundai Motor Group, Hyundai Rotem is one of the world’s largest railway system providers renowned for its world-class technology and quality. It supplies a majority of South Korea’s rolling stocks and plays a leading role in the development of railway systems in 50 countries worldwide, including large metropolitan cities such as Hong Kong, Vancouver and Philadelphia.
Manufacturers in the railway industry are constantly under pressure to bolster infrastructures, enhance services, while simultaneously achieve overall cost-reductions. Hyundai Rotem was confronted with cost-reduction challenges in the production of rolling stocks at its Brazil production plant, which was established in 2015 in Araraquara, São Paulo. Hyundai Rotem Brasil currently employs 136 staff and has a total production space of 157,850.08-meter-square.
Hyundai Rotem has been carrying out the assembly of trains at their Araraquara plant since August 2015. Rolling stocks, which are rail vehicles used in the rail transport industry, are key products of Hyundai Rotem Brasil. Made of 304 stainless steel, each rolling stock requires multiple threading processes in the train composition, such as the door groundsills, panels, seats and other structural parts. Threading processes are required for new rolling stocks as well as old ones that are in need of repair.
Hyundai Rotem’s production volume varies based on the number of trains being delivered, damaged parts and respective exchanges. On average, Hyundai Rotem performs approximately 15,000 threads per month per thread size of M4, M5 and M6 in 6H tolerance according to DIN 371 standard. It is estimated that 1,900 threads are required for each train composition. All of the processes require the threading of through-holes in depth variations of 4 mm to 25 mm. The threading process involves the use of pneumatic and electric drill drivers at cutting speed of 2,500 RPM. For the lubricant, a cutting fluid composed of highly refined mineral oil with anti-wear, anti-seize and extreme pressure additives is used.
Hyundai Rotem was originally using HSS plug taps with OX surface treatment for their production of rolling stock. These straight flute general purpose hand taps are commonly used for through hole tapping without using a starter taper tap. Hyundai Rotem was experiencing constant tool breakage throughout its production process with the plug taps.
Tool breakage is a serious production obstacle as it is costly, time-consuming, and may cause damage to the part. As a company that is always proactively responding to growing global demand and changing market environment, Hyundai Rotem Manager Daniel Bitencorte and Area Foreman Paulo Caires, who supervise the production of rolling stock, were in search of an alternative solution to improve tool life and overall cost. An opportunity for new tooling trial came about when an OSG application technician gave Hyundai Rotem a visit. After a throughout evaluation of the application, OSG recommended the A-Tap A-POT M4 (EDP# 48145144), A-POT M5 (EDP# 48145149) and A-POT M6 (EDP# 48145155).
The A-Tap is an all-purpose tap series developed to accommodate a wide variety of materials and machining environments, helping manufacturers simplify tool management. The A-Tap series includes the A-SFT spiral taps for blind holes and the A-POT point taps for through holes.
To enable high speed machining, the A-Tap series incorporates a unique cutting edge design that emphasizes sharpness. Powdered metal HSS and OSG’s patented V coating are employed in this series to enhance wear resistance. Not only does the A-Tap series perform well in general steel, it also excels in difficult-to-machine materials such as stainless steel and mild steel. As an all-purpose tap series, the A-Tap is compatible with various types of machining equipment – from manual drilling machines to the latest advanced machining centers.
With the previous tooling choice, Hyundai Rotem was using approximately 600 taps per month with each tap averaging 30 threads in tool life. When performing the same work with the A-Tap, on the other hand, each tool is able to complete 300 threads, which is 10 times the durability, resulting in excellent cost savings for Hyundai Rotem.
By switching to OSG’s A-Tap series, Hyundai Rotem is able to enhance its operation’s stability and quality control. Moreover, the services that come along with the quality products – prompt response and problem-solving ability – makes OSG a reliable partner in Hyundai Rotem’s global growth strategy.