Plate Shear Cutting

Overview of Plate Shearing

Shearing stainless steel plate or sheet is an efficient, cost effective way to cut common squares or rectangles from larger stainless steel plates that do not require internal part geometry to be cut.  Shear cutting is ideal for parts that are utilized as base plates, supports utilized in larger fabrications, construct skids, or related structural members that are incorporated into larger stainless fabrications.

Yes, Penn Stainless can shear cut 20 ft long sections of stainless steel!

Shearing Setup for Cutting Stainless Steel Plate

Shear cutting utilizes a blade to cut through stainless steel plate and sheet. A shearing set up typically consists of back gauges, clamps, a lower blade, an upper blade. The back gauges and clamps hold the cutting material in place horizontally. The lower blade is fixed in place. The upper blade moves up and down, and literally breaks the stainless plate to size. The upper blade is tilted at a very slight angle as compared to the lower blade. This angle is referred to as the rake/shear angle. Also, there is a very small clearance between the two blades. In order to achieve the best quality cut possible when shearing cutting, it is critical to establish the appropriate set up before beginning the shearing process. This includes ensuring that the stainless steel plate is held securely in place, and that the appropriate clearance between the blades and rake/shear angle is established. The recommended distance between the blades is dependent on a number of factors, including the stainless steel grade and the thickness of the material to be cut. If the clearance is too tight, it may lead to secondary shearing by the upper knife as it passes through the cut. If the clearance is too large, it may allow the material being sheared to drag over to an excessive degree, resulting in a poor cut. The rake/shear angle can have an impact on distortion of the cut stainless steel plate. Smaller rake/shear angles necessitate higher power/ force, but cause less distortion. Larger angles reduce the power/force required, but require higher hold down pressure on the clamps and tend to increase distortion[i].

[i] “Stainless Steel Fabrication Designer Handbook.” SSINA: Specialty Steel Industry of North America. Web. 08 Dec. 2011.

Decision Factors for Selecting Shearing to cut Stainless Steel Plate

Shearing stainless steel plate or sheet is an efficient, cost effective way to cut common squares or rectangles from larger stainless steel plates that do not require internal part geometry to be cut.  Shear cutting is ideal for parts that are utilized as base plates, supports utilized in larger fabrications, construct skids, or related structural members that are incorporated into larger stainless fabrications.

Benefits of Shearing:

• Cost Effective
• Fast

Limitations of Shearing:

• Shearing cannot be used to cut advanced geometric shapes.  It is limited to squares and rectangles.
• Shear Cutting places significant stresses on the cut part due to the fact that it literally breaks the material. Shearing can cause distortion (twist, camber, and bow). The risk of distortion tends to increase as the width of the cut piece decreases relative to the thickness of the material. Also, to a lesser degree, distortion increases with the length of the cut. This risk is reduced with proper set up.
• Shearing is typically limited to 5/8” inch or even less, depending on the grade. It is possible to shear through ¾” thick stainless plate, but this is not usually recommended. Because shearing literally breaks the stainless steel plate, ¾" sheared plates may require additional end preparation before welding, and add additional stress to the cut part.
• Also, it is important to note that not all grades of stainless steel can be sheared the same way. The grade of stainless steel significantly impacts what processing methods should be employed to meet the needs of a particular requirement.

Plate Shearing: Austenitic Stainless Steels: Austenitic stainless steels are characterized by a high ductility and, hence, a greater resistance to fracture. A greater degree of penetration is needed before the fracture occurs. Shear cutting work hardens the material along the sheared edge, while relieving stress in the sheared plate that accumulates during the rolling or annealing processes that is part of the standard mill manufacturing process. Given these challenges, users may want to avoid machining sheared edges when possible, particularly on plate that exceeds 3/8” thick. Plate Shearing: Ferritic Stainless Steel: Ferritic Stainless steels such as 405, 430, 439, 430F, 442 and 446 do not lend themselves to shearing over ¼” in thickness. Shearing Ferritic stainless steel may result in stress fractures beyond the sheared edge of the cut part. Cost Factors to Consider when Comparing Processing Costs In order to accurate determine the true cost of cutting when comparing processing options, it is important to consider the following: Cutting costs: Shearing is extremely low cost. It is one of the cheapest cutting methods available.

• Material costs:  Due to the fact that shearing literally breaks the material, there is no material loss during cutting. Still, parts often need to be cut to a larger overall size in order to account for additional processing that will need to be done to remove cut edges after shearing.  This extra material cost should be considered in cost calculations
• Costs of additional processing requirements: It is also important to consider the cost of any secondary processing steps. Depending on the application for which the cut material will be used, it may be possible to eliminate a secondary processing step by choosing a primary cutting process other than shearing.

Shear Cutting Stainless Steel at Penn Stainless Products

• Penn Stainless can shear cut 20 ft long sections of stainless steel!
• Penn Stainless Products has 30 years of processing experience, and provides shearing as part of our full line of processing services. This knowledge base enables us to help customers select the most cost effective processing options that best meet your needs.
• Penn Stainless’s enormous inventory of stainless steel helps ensure fast delivery times for standard, as well as hard to find products. Penn Stainless Products stocks over 30 grades of stainless steel, including 300 and 400 series stainless, duplex steels, 17-4PH, and high temperature grades.