Sheet Metal Sheer

This page contains information about the different shearing tools in Brunsfield Center & MTC.

What is shearing?

Shearing is a metal cutting process that involves applying a high force to a material so that it fails and separates along a straight line. It is primarily used for cutting sheet metal, plate, or bar stock without producing chips or melting the material. In shearing, two blades—one fixed (lower) and one moving (upper)—work together like a pair of scissors to cut through the material. The material is placed between the blades, and as the upper blade descends, it exerts enough pressure to fracture the material cleanly along the intended line.

Metal Shearing process.

Required PPE

• Safety glasses
• Work gloves
• Long pants, non-ripped
• Steel-toed boots

Safety Precautions

Before using a sheet metal foot shear, it is essential to follow standard safety procedures:

• Wear safety glasses, toe caps and gloves.

• Keep fingers and hands clear of the blade path.

• Ensure all adjustments are made with the machine disengaged and not in motion.

• Do not exceed the material thickness capacity.

Potential Hazards

• Pinch points

• Sharp blade

Treadle shear as seen in Brunsfield.

Treadle Shear

A Treddle Shear, also known as a foot-operated squaring shear, is a mechanical cutting device used in metalworking to cut straight lines through material with precision. This tool is commonly found in fabrication shops, HVAC operations, and metalworking classes due to its durability, ease of use, and ability to make clean cuts in a variety of metal types and thicknesses.

Overview

The foot shear consists of a sturdy frame, a fixed lower blade, and a moving upper blade attached to a pedal or treadle. By pressing down on the foot pedal, the operator lowers the upper blade in a shearing motion, slicing through the material placed on the cutting bed. Most foot shears are designed for cutting mild steel sheets up to 16 gauge (approximately 1.6 mm), though capacities vary by model.

Key components of a sheet metal foot shear include:

• Upper and lower blades: Hardened steel blades responsible for the shearing action.

• Foot pedal: Lever mechanism activated by foot pressure to operate the blade.

• Squaring arm: A guide used to align the material at precise right angles.

• Extension arms: Provides support for bigger pieces of material

Foot shears offer the advantage of manual control without the need for electricity or hydraulics, making them reliable and safe for classroom or light industrial use.

Safety First

1. Stay within the capacity of the shear when cutting metal
2. Sheet metal edges can be sharp after cutting; avoid running fingers along them.
3. Ensure that the blade is not dull.
4. Ensure that the metal is clamped when cutting.
5. Keep fingers away from the blades when cutting.

Clean Up Procedures

• Remove scrap pieces and place in scrap bins if usable, garbage if not.
• Put away all tools.

Compatible Materials and Thickness Limits

Sheet metal foot shears are designed to cut a variety of thin, flat metal materials. The maximum thickness the shear can handle depends on the material's hardness and the shear’s specific design and blade capacity. Exceeding these limits can damage the shear, dull the blades, or result in poor-quality cuts.

Brunsfield Center thickness limit: 16 gauge (~1.6mm/ 0.039in)

Compatible Materials:

• Mild Steel (Sheet metal)

• Aluminum

• Stainless Steel

• Some plastics (NOT ACRYLIC)

Maximum cutting width: 50’’

Factors Affecting Cutting Capacity:

• Material hardness: Harder metals like stainless steel have lower thickness limits.

• Blade condition: Dull blades reduce cutting efficiency and can affect performance.

• Machine build: Heavier-duty foot shears may handle thicker materials than light-duty models.

• Blade clearance: Properly adjusted blade gaps ensure clean cuts and reduce stress on the machine.

If consistently cutting thicker or harder materials is required, consider upgrading to a hydraulic or powered shear for better performance and safety.

1. Prepare the Material:

• Scribe marks where the material needs to be cut

• Ensure your cutting marks are accurate and visible

2. Position the Material:

• Slide the material onto the bed of the shear.

• Align the cutting mark with the blades using the squaring arm or measurement markings.

• Press the material firmly against the squaring arm or guide.

3. Secure the Material:

• Clamp or press down material to prevent shifting during the cut

4. Make the Cut:

• With both hands clear, press down firmly and steadily on the foot pedals.

• It’s more easily done with one person on each pedal.

• The upper blade will descend, shearing the metal along a straight line.

• Release the pedal to raise the blade back to its resting position.

5. Remove the Cut Material:

• Carefully retrieve both the cut piece and the remaining sheet.

• Inspect for accuracy and re-cut if necessary.

• Put away any scrap into the Scrap Bins (if reusable) or garbage

Adding the Extension Arms:

1. Identify the Mounting Location:

• Locate the threaded holes or slots on the front or side of the shear bed or table where the extension arms are designed to attach.

• These will usually be aligned with the shear’s edge and have visible bolt holes.

2. Clean the Mounting Area:

• Wipe down the surface and bolt holes to remove dust, metal shavings, or oil.

• Ensure the threads are clean for proper bolt engagement.

3. Align the Extension Arm:

• Position the extension arm so that its mounting holes line up with the shear's threaded holes.

• Arms may have adjustable brackets or slots for fine alignment.

4. Insert and Tighten the Bolts:

• Insert the bolts through the arm bracket into the shear’s mounting holes.

• Hand-tighten each bolt to hold the arm in place.

• Then, use a wrench or socket to firmly tighten the bolts evenly.

• Avoid overtightening to prevent stripping threads or distorting the arm.

5. Check for Level and Stability:

• Use a level or straightedge to ensure the extension arm is flush with the shear bed.

• Make adjustments if necessary and retighten.

Removing the Extension Arms:

1. Support the Arm:

• Hold the arm securely to prevent it from dropping when bolts are removed.

1. Loosen and Remove the Bolts:

• Using the same wrench or socket, loosen and remove each bolt.

• Place bolts and washers in a container so they’re not lost if the arms need to be reinstalled later.

1. Lift Off the Arm:

• Gently slide or lift the arm away from the shear.

• Be cautious of any sharp edges or weight, especially on larger support arms.

1. Clean the Mounting Area (Optional):

• Wipe the area clean and apply light machine oil to the threads to prevent rust if the arms will be off for a while.

Maintenance (STAFF ONLY)

Regular maintenance ensures consistent performance and longevity of the foot shear:

• Lubricate moving parts as specified by the manufacturer.

• Degrease and oil the bed and blades of the machine.

• Check and adjust blade alignment periodically.

• Replace or sharpen blades when cutting performance diminishes.

• Inspect for loose hardware and worn components.

Lever shear available in Brunsfield

Lever Shear

A lever shear, also known as a lever-operated bench shear, is a manually operated cutting tool used for slicing sheet metal and flat bar stock. It operates using mechanical leverage to multiply the user’s force, enabling clean, straight cuts without the need for electrical power.

Lever shears are commonly used in small fabrication shops, maintenance departments, and educational settings due to their affordability, portability, and simplicity.

Overview

A lever shear consists of:

• A cutting blade assembly fixed to a solid base or mounting platform.

• A long manual lever arm attached to a movable upper blade.

• A stationary lower blade affixed to the base.

By pulling the lever downward, the upper blade moves past the lower blade in a scissor-like shearing action. The length of the lever provides the mechanical advantage that allows the user to cut through metal with minimal effort.

Safety First

1. Stay within the capacity of the shear when cutting metal
2. Do not cut wire.
3. If repeated cuts are done on the same edge, it can result in sharp slivers being created. Carefully remove these with a file to prevent cuts and other injuries.
4. Keep fingers away from the blade when cutting.  
5. Leave the handle in a vertical position so that no one walks into it.
6. When not in use, ensure the shear is locked with a bolt.

Clean Up Procedures

1. Remove scrap pieces and place in scrap bins if usable, garbage if not
2. Put lever shear back in its place
3. Ensure the shear's movement is locked by a bolt

Material and Capacity

They are commonly used with metals like:

• Mild steel

• Aluminum

• Copper

• Brass

• Stainless steel (thin gauge only)

But they can also cut softer materials like rubber and some plastics.

Cutting Capacity

The cutting capacity depends on the material's hardness and the shear’s specific design and blade capacity. Exceeding these limits can damage the shear, dull the blades, or result in poor-quality cuts.

Brunsfield center thickness limit: 16 gauge (~1.6mm/ 0.039in)

Maximum Cutting Lengthː 12 in

A typical benchtop lever shear can handle:

• Mild steel up to 16–12 gauge (1.6–2.5 mm)

• Aluminum and softer metals up to 10 gauge (~3 mm)

• Flat bar up to 1/4" thick by 2" wide

Always check the manufacturer's specifications or ask staff to avoid overloading the tool.

Operating Instructions]

Step-by-Step: How to Use a Lever Shear

1. Mount the Shear (if necessary):

• Secure the shear to a sturdy workbench using bolts or clamps.

2. Mark and Position Material:

• Measure and mark the cut line on the sheet metal.

• Align the mark with the edge of the lower blade or guide.

3. Check Blade Clearance:

• Ensure the upper and lower blades are properly aligned and not damaged.

4. Engage the Lever:

• With a firm grip, pull the lever downward in a controlled motion.

• The upper blade will shear through the material as it passes the lower blade.

5. Return the Lever:

• Allow the lever to return to its upright position  

6. Remove the Cut Material:

• Carefully retrieve the cut piece and check accuracy.

Maintenance (STAFF ONLY)

Regular maintenance is necessary for the upkeep of the tools

• Degrease and oil the blades regularly to prevent rust.

• Sharpen or replace dull blades to maintain cut quality.

• Tighten any loose bolts or linkages.

• Check for proper blade clearance to ensure safe operation.