SUMITOMO GND slotting tool holder selection and troubleshooting

SUMITOMO GND slotting tool holder selection and troubleshooting

In turning machining, grooving, cutting, end face grooving, and inner hole grooving are often the processes that are most prone to exposing process problems. Problems such as vibration, poor chip removal, blade breakage, surface tearing during machining, and short tool life often require engineers to repeatedly adjust between machine tools, tool holders, blades, and cutting parameters. The GND series grooving tool holder revolves around high rigidity, vibration resistance, excellent chip removal, and rich chip breaking grooves, providing a systematic solution for small part lathes, Swiss lathes, automated production lines, and universal turning centers. This article compiles a technical guide for on-site engineers from five dimensions: product structure, chip groove selection, material matching, common troubleshooting, and practical cases.

GND series product architecture and core advantages

The GND series is not a single tool holder, but a complete product family covering outer circular groove cutting, cutting, profiling, end face groove cutting, inner hole groove cutting, neck cutting, and multifunctional processing. Its basic models include GNDM, GNDL, GNDS, GNDN, GNDI, GNDIS, GNDF, GNDFS, GNDXL, GNDZ, GNDZS, etc., and extend to GND Modular modular system and PSC polygonal tool holder system.

The integral GND handle adopts an integral structure and a mold steel blade body, which significantly improves the anti vibration ability compared to conventional blade handle. Official data shows that its high rigidity design can reduce vibration by about 30%. In the structural steel groove cutting test, the GND tool holder remained stable at a feed rate of 0.012 IPR, while conventional products showed significant vibration at 0.0031 IPR. This means that GND can achieve a processing efficiency improvement of over 300% under high feed conditions. For the processing of slender shafts, thin-walled parts, and small components, this anti vibration ability directly determines the surface quality and tool life.

The GND Modular modular system is designed for flexible production. It adopts a modular structure with coolant supply, supporting square tool holders of 0.75 inches, 1.00 inches, 1.25 inches, and 25mm, as well as PSC40, PSC50, and PSC63 polygonal tool holders. All specifications are available in 0 ° and 90 ° directions, suitable for slotting, cutting, tanker and end face slotting. Modular design reduces inventory requirements for multiple tool holders while maintaining high rigidity connections.

The blade holder size covers 1.25mm to 8.0mm, with a cutting width tolerance of ± 0.03mm. Some blades use high-precision sintering technology, which can achieve a cutting width accuracy of ± 0.0012 inches even without grinding. This is particularly important for cutting grooves in precision small parts, as groove width tolerances directly affect assembly and sealing performance.

Chip groove selection: from universal groove to cutting and copying

The GND series offers ten types of chip breakers, covering cutting, profiling, neck cutting, and non-ferrous metal processing. Choosing the right chip breaker is the first step in solving chip removal and blade breakage problems.

MG: Universal groove and transverse turning chip breaker, suitable for standard groove and transverse cutting.

ML: Low feed chip breaking groove, suitable for working conditions with small feed and limited chip space.

GG: The preferred chip breaker for universal grooving is the first recommendation for grooving applications, which balances chip control and processing stability.

GL: Low feed chip breaking groove, suitable for low feed and poor chip discharge conditions.

GF: Low cutting force chip breaker, suitable for low feed and thin-walled parts, can reduce cutting resistance.

CG: The preferred chip breaker for universal cutting, with a front angle of 5 °, is suitable for most cutting applications.

CF: Low cutting force cutting chip groove, front angle of 10 °/15 °, suitable for cutting small parts and low rigidity machine tools.

RG: Outer circle contour and radius cutting groove chip breaking groove, suitable for contour machining.

RN: End face, inner hole, neck cutting, and contour chip groove, suitable for machining with retreat or interference avoidance.

GA: Dedicated chip breaker for non-ferrous metals, suitable for materials such as aluminum and copper.

In troubleshooting, if the chips are long or tangled, ML, GL, or CF should be prioritized; if the chips are blocked in the groove, the internal cooling pressure and chip breaker groove should be checked for compatibility; If there is a central burr during cutting, a chiral CF chip breaker can be used to eliminate the burr using the direction of the cutting edge. If the tool interferes during the copying process, the RN chip groove is longer than the RG, which can effectively avoid interference between the tool holder or blade and the workpiece.

Material selection: Match according to the workpiece material

The GND series can be paired with various coated hard alloys, CBN, and PCD materials. Common materials include:

AC8025P: General processing of steel, suitable for grooving and cutting of carbon steel and alloy steel.

AC8035P: Heavy intermittent processing of steel, with stronger resistance to chipping.

AC5015S: Preferred for heat-resistant alloys and rare materials, suitable for stainless steel and high-temperature alloys.

AC5025S: Heat resistant alloy with heavy intermittent processing, suitable for strong intermittent working conditions.

AC530U/AC1030U: Universal material, covering most materials.

AC425K: Processing of cast iron and ductile iron.

T2500A: Precision machining of steel and stainless steel.

H10/DL1500: Processing of non-ferrous metals.

BN7500: CBN material for powder metallurgy.

In grooving and cutting, material selection should take into account both wear resistance and anti chipping performance. For example, cutting stainless steel is prone to work hardening and adhesion, so AC5015S or AC5025S should be preferred; Carbon steel and alloy steel slots can be cut using AC8025P or AC8035P; Choose AC425K for cast iron groove cutting. For cutting small parts, CF chip breaker combined with AC5015S can achieve stable chip removal and long lifespan at low feed rates.

Common troubleshooting and solution strategies

1. Vibration and chatter

Vibration is the primary issue in grooving and cutting. The solution includes: using GND integral handle or GND Modular high rigidity system; Try to shorten the overhang of the handle as much as possible; Adjust the center height. When cutting grooves and turning horizontally, the center height should be controlled within ± 0.1mm. When cutting, it is recommended to have a center height of 0 to+0.2mm. Use an internal cold tool holder and spray coolant directly onto the cutting edge; Check whether there are burrs or foreign objects on the installation surface of the blade holder and handle.

2. Poor chip removal

Chip blockage can cause blade breakage and surface scratches. The GND series improves chip removal through a combination of wide pocket design, internal cooling oil holes, and chip breaking grooves. Under a cooling pressure of 1000 PSI, the tool life of GNDM-J and GNDL-J internal cooling tool holders can reach 7 times that of conventional external cooling. For cold processing of small holes, the GNDIS and GNDI series offer groove cutting solutions for inner holes with minimum diameters of 14mm and 32mm. If the chip removal is still not smooth, the feed can be reduced, the cooling pressure can be increased, or GL/CF chip breaker can be used instead.

3. Broken blade

Blade breakage is usually caused by vibration, intermittent impact, or insufficient material toughness. Countermeasure: Choose anti collapse blade materials such as AC8025P and AC8035P; Reduce feed per tooth or adopt variable feed; Use RN chip breaker to avoid interference; In cutting applications, avoid pulling out the blade, ensure that the blade slides parallel into the blade seat during installation, and tighten according to the recommended torque.

4. Pull out or loosen the blade

The GND blade adopts a clamping structure, and during installation, the blade needs to be slid parallel into the blade seat and pushed to the bottom, so that the back of the cutting edge is against the constraint surface. Use the recommended torque for tightening to avoid damaging the blade or handle with excessive torque. The 12mm and 16mm square handle of GNDL/GNDM for internal cooling small parts supports blade replacement from the top and bottom, making it convenient for automated production line maintenance.

5. Poor surface quality during processing

Poor surface quality is often related to vibration, improper center height, insufficient sharpness of the cutting edge, or insufficient cooling. The GND series offers sharp groove types such as GF and CF, suitable for low feed precision machining; Internal cooling handle can effectively cool the cutting edge, reduce chip accumulation and tearing. In the cutting groove of the 304 stainless steel measuring component, GND, combined with internal cooling and suitable chip breaking groove, achieves stable chip removal and longer service life.

6. Short tool life

Short tool life needs to be investigated from four aspects: material, chip groove, cooling, and cutting parameters. In the case of cutting pure iron automotive parts, GNDMR616JX-216J, combined with GCMN2002-GF and internal cooling, has a lifespan of 10000 pieces, which is four times that of the competitor's 2500 pieces. In the cutting groove of the sintered part tapping component, GNDLL2020K-220J is matched with GCMN2002-GF, with an internal cooling of 218 PSI, and the service life is 1.7 times that of the competitor. It can be seen that internal cooling and material matching have a significant impact on lifespan.

Practical cases and selection references

4130 steel end face profile: GNDFR2525M-423-125, GCMN4020-RN, vc=660 SFM, f=. 0055 IPR, wet cut. High rigidity, good chip removal, and no vibration.

1045 steel valve cut-off: GNDMR2525M-312, GCMN3002-ML, vc=500 SFM, f=. 002-0.006 IPR, wet cut. Stable without vibration.

H13 steel cutting (45-48HRC): GNDLR2525M-425, GCMN4002-GG, vc=165 SFM, f=. 0012, wet cutting. Prevent accidental blade breakage.

304 stainless steel measuring component groove: GND internal cooling, stable chip removal, and improved lifespan.

Cutting groove for 1015 steel automotive parts: GNDMR2525K-312, GCMN3004-GG, vc=500 SFM, f=0.0039 IPR, internal cooling 305 PSI. Cutting time 1.2 seconds per piece, competitor 3.6 seconds per piece; Lifespan of 1000 pieces, competing with 250 pieces.

Cutting of pure iron automotive parts: GNDMR616JX-216J, GCMN2002-GF, vc=475 SFM, f=. 0023 IPR, internal cooling. Lifespan of 10000 pieces, competing with 2500 pieces.

Sintered part tapping component groove cutting: GNDLL2020K-220J, GCMN2002-GF, vc=300 SFM, f=0.008 IPR, internal cooling 218 PSI. 50 pieces of lifespan, 30 pieces of competitors.

Key points for installation, cooling, and maintenance

Before installing the GND handle, clean the blade holder, bolts, and bolt holes to remove burrs. The blade slides parallel to avoid tilting. The handle should be perpendicular to the workpiece and the overhang should be as short as possible. Lock the center height after adjustment. The internal cooling knife handle should be correctly connected to the coolant pipeline, with sealed joints to avoid leakage. For non hose cooling supply, liquid can be supplied directly from the tool holder connection point. Recommend using filtered coolant to prevent oil hole blockage. Regularly check the wear and clamping force of the blade holder, and replace the handle or clamping components if necessary.