A sheet metal shear should be selected from the buyer’s real material list and part mix. The nameplate thickness is only meaningful when it states the reference material strength, maximum cutting width and conditions under which that capacity applies.
Browse the current shearing and cutting machine category before comparing configurations.
1. Define Capacity with Material Strength and Cutting Width
Do not convert carbon-steel capacity to stainless-steel capacity with a fixed 2:1 rule. Ask the supplier for the rated tensile-strength basis and a capacity table for every material grade you plan to cut. High-strength steel, hardened sheet and nonferrous alloys can behave very differently at the same thickness.
- Maximum and normal production thickness for each material grade.
- Maximum cutting length, normal part width and whether full-length capacity is required.
- Minimum strip width, short-part handling and front/rear support requirements.
- Daily cut count, batch size and frequency of thickness changes.
- Required burr, straightness, squareness and flatness after cutting.
2. Choose the Shear Type
Hydraulic guillotine shears guide the upper beam in a near-vertical motion and often provide adjustable rake and gap on higher configurations. Swing-beam shears move the blade through an arc and can offer a simpler, economical solution. The better choice depends on capacity, part quality, adjustment range, duty and maintenance access.
Use the detailed guillotine vs swing beam shearing machine comparison to separate the two mechanisms.
| Question | Why it matters | Evidence to request |
|---|---|---|
| Is rake adjustable? | Changes force and deformation behavior | Range and control method |
| Is blade gap adjustable? | Matches material/thickness | Manual, centralized or automatic method |
| How is the sheet held? | Prevents lifting and movement | Hold-down layout and pressure control |
| How is the part supported? | Affects safety and flatness | Front arms, rear support or return system |
| How is capacity stated? | Prevents material-rating errors | Strength basis and full-width table |
3. Understand Rake Angle and Blade Gap
A larger rake angle can reduce peak cutting force because less blade length engages at once, but it can increase twist or bow in narrow strips. A smaller rake can improve part behavior in some work, yet it may increase load. Stay inside the machine manufacturer’s approved range.
Blade gap controls how the material fractures between the upper and lower blades. Too much or too little gap can increase burr, edge rollover, load, rubbing and blade damage. Set it from the machine’s chart or controller using the actual material and thickness, then verify with a trial cut.
One guillotine reference is the QC11Y hydraulic guillotine shearing machine.
For a swing-beam reference, compare the QC12K Series swing beam shear.
4. Size the Backgauge from the Parts
There is no universal 600 mm standard that fits every buyer. Map the backgauge travel to finished part dimensions, squaring method and production sequence. Also confirm speed, repeatability, finger arrangement, collision limits, retract function and whether long or thin sheets need additional support.
- NC control can be suitable for straightforward single-axis backgauge positioning and repeated cuts.
- CNC control becomes more valuable when the job needs stored programs, multiple steps, automatic compensation, additional axes or integration with support and handling systems.
- Controller labels alone do not guarantee capability. Ask for the actual axis list, screen demonstration and a cycle using one of your parts.
5. Send a Complete Buying Specification
| Category | Required buyer input | Supplier response |
|---|---|---|
| Material | Grades, strengths and thickness range | Rated table and exclusions |
| Parts | Cut length, strip width, tolerances | Suitable type and configuration |
| Production | Cuts/day, batch changes, handling | Cycle time and support equipment |
| Control | Programs, axes and automation | NC/CNC functions demonstrated |
| Site | Power, layout, unloading and safety | Installation drawing and requirements |
| Acceptance | Sample parts and measurements | Trial-cut report and agreed criteria |
Use the wider China sheet metal machinery buying checklist for factory, documentation and delivery checks.
Sheet Metal Shear FAQs
Can a carbon-steel rating be used for stainless steel?
Not directly. Compare the actual grade and tensile strength with the manufacturer’s approved capacity table.
Is a larger rake angle always better?
No. It can reduce peak force but may increase deformation in narrow strips. Use the smallest approved setting that satisfies capacity and cut quality for the application.
When is CNC worth the additional cost?
CNC is valuable for multi-step jobs, stored programs, compensation, multiple axes and automation. Simple repeated dimensions may only need an NC backgauge.
What should be tested before shipment?
Cut the buyer’s materials at normal and demanding sizes, then record burr, dimensions, squareness, flatness, repeatability and cycle time.
Send the material list and part drawings through the BEIGEMA contact page.
