PressEquip
Civil/Environmental
- Oct 26, 2009
- 35
Requesting feedback on tool steel material recommendation for nut splitter wedge. Used to split seized nuts, typically A-194 2H [Nuts have max hardness of 38 HRC (327 Brinell)], nut batches are proof load tested based on proof stress of 175 ksi.
In the past, the trades men at the company decided upon M2 tool steel for making the wedges. I developed a heat treating procedure for Austenitize and then quench and temper, required hardness: 62 - 64 HRC. Heat treatment is done in a atmospherically controlled furnace. Hardness testing is done at the end to ensure hardness is in the acceptable range. A hydraulic ram pushes the wedge into the nut to split the nut. The wedge doesn’t get hot, so we could use a low speed tool steel or other suitable grade of steel. But I recently got feedback from the field that the M2 steel wedges aren't holding up well, only splitting a couple nuts and then failing prematurely by brittle fracture.
The tool by hydraulic force puts the wedge in bearing with the seized nut. The wedge is loaded in compression.
I also wonder what material is used in bolt cutter for the jaws. Also the Jaws of Life, used for cutting apart automobiles are the site of accidents, what material is used.
M2 is a high speed tool steel, like for boring tools. Typical Applications include Broaches, Boring Tools, Chasers, Cold Forming Rolls, Cold Heading Inserts, Drills, End Mills, Form Tools, Hobs, Lathe and Planer Tools, Punches, Milling Cutters, Taps, Reamers, and Saws.
Nut splitting isn’t a high speed activity, the wedge probably won’t heat up.
It might make sense to consider changing materials to a tool steel that is good for heavy duty compression tool like H11 or H13, which is also used to make shear blades (similar to how the wedge splits the nut). There are some other grades of tool steel that are also used to make shear blades: D2, A6, A2 DCF, L6, S5. It might be worth considering those grades of steel as well.
Below from the internet
H11 is a chromium-based steel alloy from the “H” family of steels according to the AISI classification system. H11 is one of the most commonly used alloys from this group, thanks to the outstanding impact toughness. Other steels from this group, such as the H13 have more vanadium, which gives better wear resistance and temper resistance, but worse impact toughness. H11 is also used for hot tooling applications thanks to its excellent resistance to cracking, including thermal fatigue cracking, gross cracking and thermal shock during water cooling. These include hot punches, die casting dies, forging dies, hot shear blades, hot gripper dies, and extrusion tooling. Like most steels with high toughness and low carbon content, Steel H11 can be used for producing hot-work steels with the water-cooling method. H11 has minimal distortion during deep-hardening and air-hardening thanks to the balanced alloy content. H11 can also be hardened with an air quenching method.
H13 is a 5% chromium hot work tool steel designed for applications that require extreme toughness combined with good red-hardness. H13 will allow an extra margin of safety in tools subject to heavy hammer blows, and those containing deep recesses or sharp corners. Although H13 was designed as a hot work steel, it has solved many cold work applications where extra toughness could be gained with some sacrifice of wear resistance.
Typical Applications: Aluminum Extrusion Dies, Die Casting Dies, Heavy Duty Compression Tools, Forming Punches, Hot Forging Dies, Shear Blades, Plastic Mold Dies, and Bolt Dies.
D2 is an air-hardening, high carbon, high chromium tool steel with extremely high wear resisting properties. It is a very deep hardening steel and will be practically free from size change after proper treatment. The high percentage of chromium gives it mild corrosion resisting properties in the hardened condition.
Typical Applications: Blanking Dies, Forming Dies, Coining Dies, Slitting Cutters, Heading Tools, Long Punches, Forming Rolls, Edging Rolls, Master Tools, Beading Rolls, Intricate Punches, Extrusion Dies, Drawing Dies
A6 is an air-hardening, non-deforming tool steel that combines the deep hardening characteristics of air-hardening steels with the simplicity of low temperature heat treatment possible in many of the oil-hardening grades.
Typical Applications: Blanking Dies, Precision Tools, Forming Dies, Coining Dies, Master Hubs, Shear Blades, Plastic Molds, Spindles, Mandrels, Heavy Duty Punches.
A2 DCF Tool Steel is an air-hardening grade of steel that contains 5% chromium. A2 is noted for its good toughness and excellent dimensional stability in heat treatment. Replaces the oil hardening (O1 type) when safer hardening, less distortion and increased wear-resistance are required. These characteristics make it a versatile tool steel that combines good performance and price. A2 Steel falls between oil-hardening and D2 high-carbon, high chromium tool steels.
Typical Applications: Large Blanking Dies, Thread Roller Dies, Long Punches, Rolls, Master Hubs, Trimming Dies, Forming Dies, Precision Tools, Gauges, Coining Dies, Extrusion Dies, Mandrels, Shear Blades and Slitters.
L6 is a tough, oil-hardening tool steel possessing a fine-grained structure and desirable shock resistance. L6 is also associated with high strength and good non-deforming characteristics.
Typical Applications: Forming Rolls, Spindles, Punches, Trim Dies, Blanking Dies, Embossing Dies, Forming Dies, and Shear Blades.
S5 is an oil-hardening silicon-manganese steel of medium carbon content especially adapted for punches, shear blades, chisels, and other shock resisting applications. S5 is therefore applicable where the properties of silicon-manganese steels are desired in combination with well-known advantages of oil-hardening steels. A reduced tendency to distort or crack in heat treatment is accordingly combined with high toughness in S5.
Do you think we should consider changing from M2 tool steel to another grade of steel for this application? If so, what grade of tool steel and what harness range to aim for?
Thanks in advance for the feedback!
A Fan of EngTips, share the knowledge
In the past, the trades men at the company decided upon M2 tool steel for making the wedges. I developed a heat treating procedure for Austenitize and then quench and temper, required hardness: 62 - 64 HRC. Heat treatment is done in a atmospherically controlled furnace. Hardness testing is done at the end to ensure hardness is in the acceptable range. A hydraulic ram pushes the wedge into the nut to split the nut. The wedge doesn’t get hot, so we could use a low speed tool steel or other suitable grade of steel. But I recently got feedback from the field that the M2 steel wedges aren't holding up well, only splitting a couple nuts and then failing prematurely by brittle fracture.
The tool by hydraulic force puts the wedge in bearing with the seized nut. The wedge is loaded in compression.
I also wonder what material is used in bolt cutter for the jaws. Also the Jaws of Life, used for cutting apart automobiles are the site of accidents, what material is used.
M2 is a high speed tool steel, like for boring tools. Typical Applications include Broaches, Boring Tools, Chasers, Cold Forming Rolls, Cold Heading Inserts, Drills, End Mills, Form Tools, Hobs, Lathe and Planer Tools, Punches, Milling Cutters, Taps, Reamers, and Saws.
Nut splitting isn’t a high speed activity, the wedge probably won’t heat up.
It might make sense to consider changing materials to a tool steel that is good for heavy duty compression tool like H11 or H13, which is also used to make shear blades (similar to how the wedge splits the nut). There are some other grades of tool steel that are also used to make shear blades: D2, A6, A2 DCF, L6, S5. It might be worth considering those grades of steel as well.
Below from the internet
H11 is a chromium-based steel alloy from the “H” family of steels according to the AISI classification system. H11 is one of the most commonly used alloys from this group, thanks to the outstanding impact toughness. Other steels from this group, such as the H13 have more vanadium, which gives better wear resistance and temper resistance, but worse impact toughness. H11 is also used for hot tooling applications thanks to its excellent resistance to cracking, including thermal fatigue cracking, gross cracking and thermal shock during water cooling. These include hot punches, die casting dies, forging dies, hot shear blades, hot gripper dies, and extrusion tooling. Like most steels with high toughness and low carbon content, Steel H11 can be used for producing hot-work steels with the water-cooling method. H11 has minimal distortion during deep-hardening and air-hardening thanks to the balanced alloy content. H11 can also be hardened with an air quenching method.
H13 is a 5% chromium hot work tool steel designed for applications that require extreme toughness combined with good red-hardness. H13 will allow an extra margin of safety in tools subject to heavy hammer blows, and those containing deep recesses or sharp corners. Although H13 was designed as a hot work steel, it has solved many cold work applications where extra toughness could be gained with some sacrifice of wear resistance.
Typical Applications: Aluminum Extrusion Dies, Die Casting Dies, Heavy Duty Compression Tools, Forming Punches, Hot Forging Dies, Shear Blades, Plastic Mold Dies, and Bolt Dies.
D2 is an air-hardening, high carbon, high chromium tool steel with extremely high wear resisting properties. It is a very deep hardening steel and will be practically free from size change after proper treatment. The high percentage of chromium gives it mild corrosion resisting properties in the hardened condition.
Typical Applications: Blanking Dies, Forming Dies, Coining Dies, Slitting Cutters, Heading Tools, Long Punches, Forming Rolls, Edging Rolls, Master Tools, Beading Rolls, Intricate Punches, Extrusion Dies, Drawing Dies
A6 is an air-hardening, non-deforming tool steel that combines the deep hardening characteristics of air-hardening steels with the simplicity of low temperature heat treatment possible in many of the oil-hardening grades.
Typical Applications: Blanking Dies, Precision Tools, Forming Dies, Coining Dies, Master Hubs, Shear Blades, Plastic Molds, Spindles, Mandrels, Heavy Duty Punches.
A2 DCF Tool Steel is an air-hardening grade of steel that contains 5% chromium. A2 is noted for its good toughness and excellent dimensional stability in heat treatment. Replaces the oil hardening (O1 type) when safer hardening, less distortion and increased wear-resistance are required. These characteristics make it a versatile tool steel that combines good performance and price. A2 Steel falls between oil-hardening and D2 high-carbon, high chromium tool steels.
Typical Applications: Large Blanking Dies, Thread Roller Dies, Long Punches, Rolls, Master Hubs, Trimming Dies, Forming Dies, Precision Tools, Gauges, Coining Dies, Extrusion Dies, Mandrels, Shear Blades and Slitters.
L6 is a tough, oil-hardening tool steel possessing a fine-grained structure and desirable shock resistance. L6 is also associated with high strength and good non-deforming characteristics.
Typical Applications: Forming Rolls, Spindles, Punches, Trim Dies, Blanking Dies, Embossing Dies, Forming Dies, and Shear Blades.
S5 is an oil-hardening silicon-manganese steel of medium carbon content especially adapted for punches, shear blades, chisels, and other shock resisting applications. S5 is therefore applicable where the properties of silicon-manganese steels are desired in combination with well-known advantages of oil-hardening steels. A reduced tendency to distort or crack in heat treatment is accordingly combined with high toughness in S5.
Do you think we should consider changing from M2 tool steel to another grade of steel for this application? If so, what grade of tool steel and what harness range to aim for?
Thanks in advance for the feedback!
A Fan of EngTips, share the knowledge
