SUMITOMO EGU chip breaker selection and troubleshooting

SUMITOMO EGU chip breaker selection and troubleshooting

In turning, grooving, and contour machining, chip control and chatter suppression are often the core factors determining machining efficiency and tool life. The Positive EGU chip breaker is a universal positive angle chip breaker designed around these two pain points, positioned for light to medium cutting, balancing sharpness and anti chipping performance. For engineers in the "search for solutions" stage, understanding the slot structure, applicable boundaries, and common troubleshooting paths of EGU can significantly reduce the number of trial cuts and improve process stability.

The design logic of Positive EGU

The core features of Positive EGU chip breaker can be summarized into four points: wide chip pocket, low cutting resistance, raised chip control design, and dual rake edge structure.

Firstly, the wide chip pocket provides ample space for curling and discharging chips. In light to medium cutting, chips are prone to form long strips or entanglements, and wide pockets can accommodate more chips, reducing clogging and secondary cutting. Secondly, low resistance design reduces cutting forces, which is particularly important for processing slender shafts, thin-walled sleeves, and small parts. Thirdly, the raised design is not simply a chip blocking platform, but guides the flow of chips through a smooth inclined surface, suppressing chip accumulation while controlling the chips. Fourthly, the dual front corner structure adopts different angle combinations at the corners and cutting edges, ensuring that the cutting edge remains sharp and has sufficient strength. The corners adopt smaller front angles and larger back angles, while the cutting edge adopts larger front angles and moderate back angles, thus achieving a balance between light cutting and medium cutting.

From the cross-sectional parameters, the EGU has a front angle of about 5 ° and a back angle of about 15 °, and a blade front angle of about 25 ° and a back angle of about 8 °. This combination reduces the resistance of the cutting edge during cutting, while the strength of the cutting edge is sufficient to handle slight interruptions and moderate feed. Compared with conventional positive angle chip breakers, EGU has a wider range of applications, covering from precision machining to medium rough machining.

Guidelines for selecting chip breakers: boundaries between EGU and ELU, ESU, and EMU

Positive EGU is not an isolated product, but a universal core in the chip breaker series. The selection logic is as follows:

EGU: Universal chip breaker, suitable for light to medium cutting. The balance between blade strength and sharpness, stable chip control, is the preferred choice for most turning, grooving, and profiling processes.

ELU: Precision machined chip breaker, suitable for extremely shallow cutting depths and small feed rates. The cutting edge is sharper, and the chip control tends towards smaller cutting depths, suitable for precision machining with high surface quality requirements.

ESU: Light cutting chip breaker, suitable for small cutting depths and low feed rates. The blade strength is slightly higher than ELU, suitable for light load precision machining and vibration prone working conditions.

EMU: Medium to rough machining chip breaker, suitable for large cutting depths and high feed rates. The edge strength is higher, but the cutting resistance increases accordingly, making it suitable for stable and rigid working conditions.

In practical selection, if the use of EGU results in excessively long or tangled chips, you can try increasing the feed rate or cutting depth; If there is a blade breakage, it is necessary to check whether it exceeds the scope of application of EGU, and if necessary, downgrade to ELU or ESU, or upgrade to EMU. If there is vibration, priority should be given to checking the rigidity, overhang length, and center height of the handle before considering using a low resistance groove type.

Chip control and anti vibration performance

Chip control is EGU's strength. In the low to medium cutting range, EGU can suppress chip entanglement and chip accumulation. Tests have shown that EGU exhibits good chip consistency in the boring of low-carbon steel pipe inner holes within the range of feed rate 0.0039 to 0.0118 IPR and cutting depth 0.0197 to 0.0984 inches. Compared with competitors, EGU has smoother chip removal and shorter chip morphology under high feed conditions, reducing the risk of entanglement.

In terms of anti vibration, the protruding design of EGU has a smooth slope, which can reduce cutting force fluctuations. In the inner hole boring test, a steel tool holder with a length to diameter ratio of 3 was used, and the machined surface of EGU remained smooth even at a feed rate of 0.0118 IPR and a cutting depth of 0.039 inches; And competitor A has obvious surface defects. At a feed rate of 0.0079 IPR and a cutting depth of 0.059 inches, EGU remained stable, while competitor A exhibited vibration patterns. This indicates that EGU has good anti vibration ability under moderate cutting depth and high feed, especially suitable for machining inner and slender holes.

Anti collapse blade and tool life

Positive EGU adopts a double front corner shape, balancing sharpness and blade strength. In the light intermittent cutting of 4135 chromium molybdenum steel outer circle, the impact frequency of EGU reached 9200 times, while that of competitor B was 5700 times and competitor C was 6200 times, with a lifespan increase of about 1.6 times. From the perspective of failure mode, both competitors B and C have experienced blade breakage, while EGU only shows normal wear. This indicates that the blade structure of EGU can effectively disperse impact stress and suppress micro blade expansion under light intermittent working conditions.

In the external contour modeling of 4130 automotive drive components, EGU is matched with AC8025P material, with a cutting speed of 720 SFM, a feed rate of 0.0079 IPR, a cutting depth of 0.0197 inches, and wet cutting. Compared with conventional products, EGU significantly improves chip winding problems and enhances processing efficiency. In the internal hole profiling of 4130 precision mechanical components, EGU is matched with AC6040M material, with a cutting speed of 425 SFM, a feed rate of 0.0079 IPR, a cutting depth of 0.0197 inches, and wet cutting. EGU suppresses the increase in cutting edge temperature, reduces wear and damage, while competitor A exhibits significant crescent wear.

Recommended cutting parameters and material matching

Positive EGU can be paired with various materials, including carbon steel, alloy steel, stainless steel, cast iron, and heat-resistant alloys. The recommended parameters are as follows:

Low carbon steel and structural steel: AC8015P, AC8025P, AC8035P, cutting speed 525-1375 SFM, feed rate 0.0047-0.0118 IPR, cutting depth 0.0197-0.0984 inches.

Carbon steel, alloy steel (1045, 4135, etc.): AC8015P, AC8025P, AC8035P, cutting speed 460-1246 SFM, feed 0.0039-0.0118 IPR, cutting depth 0.0157-0.0984 inches.

Austenitic stainless steel: AC6020M, AC6030M, AC6040M, cutting speed 295-690 SFM, feed rate 0.0039-0.0118 IPR, cutting depth 0.0157-0.0984 inches.

Gray cast iron: AC4010K, cutting speed 650-2300 SFM, feed rate 0.0039-0.015 IPR, cutting depth 0.020-0.240 inches.

Ductile iron: AC4015K, cutting speed 525-1300 SFM, feed rate 0.0039-0.020 IPR, cutting depth 0.020-0.240 inches.

Heat resistant alloys (nickel based, iron-based, cobalt based): AC5015S, cutting speed of 90-300 SFM, feed rate of 0.0031-0.0098 IPR, cutting depth of 0.0157-0.0787 inches.

In grooving and profiling, the feed range of EGU typically covers 0.002-0.012 IPR, and the cutting depth covers 0.015-0.120 inches. For small part lathes and Swiss lathes, EGU's low resistance characteristics can reduce bending and vibration of slender parts, making it a universal choice among regular angle blades.

Practical case: From automotive parts to bearing parts

4130 car drive component outer circle imitation: using DCMT32.51EGU-AC8025P, vc=720 SFM, f=. 0079 IPR, ap=. 0197 inches, wet cut. EGU has improved chip winding, increased processing efficiency, and surface quality compared to conventional products.

4130 Precision Mechanical Component Inner Hole Imitation: Using TPMT221EGU-AC6040M, vc=425 SFM, f=. 0079 IPR, ap=. 0197 inches, wet cut. EGU suppresses the increase in cutting edge temperature, reduces wear and damage, while competitor A exhibits significant crescent wear.

4130 Automotive Parts Internal Conical Hole Boring: Use CPMT322EGU-AC8025P, vc=660 SFM, f=. 0079 IPR, ap=. 0787 inches, wet cut. EGU has good chip control at a cutting depth of 2.0mm, while competitors experience chatter under the same conditions and are not suitable. EGU has shorter chips and more stable chip discharge when cutting at a depth of 1.0mm.

5015 fastener inner hole boring: using CCMT32.52EGU-AC8025P, vc=625 SFM, f=. 0098 IPR, ap=. 0394 inches, wet cut. The strong cutting edge design of EGU enables the tool life to reach 1.5 times that of competitor B.

52100 Bearing Component Inner Hole Boring: Use DCMT32.53EGU-AC8025P, vc=720 SFM, f=. 0059 –. 0138 IPR, ap=. 0315 –. 1496 inches, wet cut. The strong cutting edge design of EGU has increased the tool life to 1.3 times that of competitor C, and the machining quantity has increased from about 280 pieces to 400 pieces.

These cases demonstrate that EGU can balance chip control, anti vibration, and tool life in precision machining of industries such as automobiles, bearings, and fasteners. It is particularly suitable for inner hole profiling, outer circle profiling, and inner cone hole boring.

Available models and materials

Positive EGU offers a variety of blade shapes and specifications, including CCMT, CPMT, DCMT, SCMT, TPMT, VBMT, VCMT, and more. Common models include CCMT21.51EGU、CCMT21.52EGU、CCMT32.51EGU、CCMT32.52EGU、CCMT432EGU、DCMT21.51EGU、DCMT21.52EGU、DCMT32.50.5EGU、DCMT32.51EGU、DCMT32.52EGU、DCMT32.53EGU、SCMT32.51EGU、SCMT32.52EGU、SCMT432EGU、TPMT221EGU、TPMT222EGU、TPMT331EGU、TPMT332EGU、VBMT221EGU、VBMT222EGU、VBMT331EGU、VBMT332EGU、VCMT331EGU、VCMT332EGU  Wait. The material covers AC8015P, AC8025P, AC8035P, AC6040M, AC5015S, AC4010K, AC4015K, etc., and can be selected according to the workpiece material.

Quick troubleshooting for common faults

Chip wrapping: Increase feed or cutting depth, check if the chip groove matches; EGU is suitable for light to medium cutting, and if the feed rate is too low, ELU or ESU can be used instead.

Flutter: Shorten the handle overhang, adjust the center height, and check the cleanliness of the blade seat; The low resistance design of EGU can suppress vibration, but if vibration still occurs, the cutting depth needs to be reduced or a sharper groove type needs to be used instead.

Broken blade: Check if it exceeds the applicable range of EGU; Can reduce the feed rate or switch to a stronger EMU; If it is intermittent impact, materials with better toughness can be selected.

Poor surface quality: check center height and cooling; EGU has good chip removal under high feed rate. If the surface tears, the cutting speed can be increased or materials such as AC6040M can be used instead.

Short tool life: Check the material and match the workpiece; Stainless steel priority AC6020M/AC6030M, carbon steel priority AC8025P/AC8035P, heat-resistant alloy priority AC5015S.