90° Knife Edge Square Ruler – Grade 1 Stainless Steel, 4 Sizes
90° Knife Edge Square Ruler – Grade 1 Stainless Steel, 4 Sizes
Precision 90° Knife Edge Square Ruler – Professional Grade 1 Accuracy
Achieve flawless right-angle measurements every time with this L-Shape Knife Edge Square Ruler. Crafted from high-quality stainless steel and ground to Grade 1 accuracy, this angle square is an essential tool for machinists, woodworkers, engineers, and craftspeople who demand precise layout and measurement work.
Key Specifications
- Material: Stainless Steel
- Available Sizes: 63×40 mm | 80×50 mm | 100×63 mm | 125×80 mm
- Edge Angle: 30° Knife Edge (bevelled on both sides)
- Seat Width: 5 mm
- Accuracy: Grade 1
- Squareness Tolerance: 0.02–0.05 mm
- Country of Origin: Made in China
Why Choose This Knife Edge Square?
- ✅ Light-Gap Method Compatible: The double-bevelled 30° knife edge blade makes it perfect for checking squareness using the light-gap method — spot even the tiniest deviation instantly.
- ✅ Ground & Lapped for Parallelism: Both beams and blades are precision-ground and lapped, ensuring consistent, repeatable measurements across every use.
- ✅ Grade 1 Precision: With a squareness tolerance of just 0.02–0.05 mm, this ruler meets the demands of professional-level layout and inspection work.
- ✅ Protective Case Included: Each ruler ships in a dedicated protective case to preserve the precision edges and keep the tool in perfect condition between uses.
- ✅ Multiple Size Options: Choose the size that best fits your workpiece — from compact 63×40 mm up to the larger 125×80 mm format.
Ideal Applications
This knife edge square ruler is designed for precision layout, squareness checking, and measurement verification across a wide range of industries and hobbies, including:
- Machining & metalworking
- Woodworking & cabinetmaking
- Engineering & quality control inspection
- Tool & die making
- DIY precision projects
What's in the Box?
- 1 × L-Shape Knife Edge Square Ruler
- 1 × Protective Case
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Frequently Asked Questions
Q: What sizes does the L-Shape Knife Edge Square Ruler come in?
A: The ruler is available in four sizes: 63×40 mm, 80×50 mm, 100×63 mm, and 125×80 mm, so you can choose the right format for your specific measurement or layout task.
Q: What does "Grade 1 accuracy" mean for this square ruler?
A: Grade 1 is a professional precision classification. It means the squareness tolerance of this knife edge square is just 0.02–0.05 mm, making it suitable for demanding machining, engineering, and inspection applications where tight tolerances are essential.
Q: How is the knife edge square used to check squareness?
A: Place the beam (stock) flat against a reference surface and bring the 30° knife-edge blade against the workpiece edge. Hold the assembly up to a light source — any visible light gap between the blade and the workpiece reveals deviation from true 90°. This is known as the light-gap method and is a standard technique in precision measurement.
Q: Does this ruler come with any protective storage?
A: Yes. Each L-Shape Knife Edge Square Ruler is supplied with a dedicated protective case to safeguard the precision-ground edges and ensure the tool stays accurate over its lifetime.
Production & Packaging Notice
To maintain high stock availability and fast shipping times, our items are sourced from multiple verified manufacturing facilities. While the core quality, materials, and product specifications remain identical, you may notice slight variations in the packaging design, manufacturing origin, or the wording of the printed instructions.