Selecting Shear Blade Alloys

Considerations in selecting the proper shear blade alloy

Mark I

Manufactured from select Premium HCHC (High Carbon, High Chrome)

Mild Steel
Maximum 1/4" thick on mechanical shears
Maximum 5/8" thick on hydraulic shears

Stainless
Not to exceed 50% of machine capacity

Mark II

Modified Premium grade alloy tool steel to provide maximum toughness and shock resistance

Mild Steel
Up to 1" thick

Stainless
Up to 50% of machine capacity

Information on shear blades differs between manufacturers as to what the suggested shear blade clearances are for various materials. The difference is due to the design of particular machines and what would be the best shear blade clearance in light of their particular design. Be sure to check the manual for your shear machine.

Should information on shear blade clearance not be available, general rule would be to set the shear blade clearance at 7% of the material thickness of the material being sheared.

The amount of clearance between the upper and lower shear blades will have a definite impact on the quality of the cut. Setting the shear blade clearances too tight will increase the tonnage required and also cause the piece to have a burnished appearance of the edge. Shear blades set with a too wide a clearance may reduce the tonnage required but will also incur some bending at the edges of the cut.

The following chart will give the optimal appearance to the cut edge. These shear blade clearances may be increased if the appearance of the cut edge is of no importance. At the same time it will reduce the amount of tonnage required.