In the Bonanomi precision mechanical workshop, we produce various clamping systems for machine tools, including G25 cast iron clamping squares. At every stage of manufacture, we comply with DIN standards.

The clamping squares made by Bonanomi are elements used in many fields of precision mechanics, both for chip removal and for geometric and dimensional control. As cast iron angle plates with a vertical reference plane, they can also be used as an angle plate for inspection to verify the squareness of the workpiece.

The main feature of the clamping squares is a vertical plane — machined either with T-slots or in a zero point version — orthogonal to the support base in accordance with DIN 875. This standard defines the maximum deviations that the vertical plane — effectively a precision 90-degree angle plate — can have from the base.

Clamping systems for machine tools and clamping squares

Generally used on chip-removing machine tools, the clamping square provides a substantial advantage in terms of workpiece machining: this structure allows better use of the machine worktables (especially for moving-column milling machines), ensuring that several workpiece faces can be reached with a single set-up, speeding up cycle times and allowing operators to save resources, with a positive impact on machining dynamics.

Among the various clamping systems for machine tools, the square is particularly effective for clamping workpieces on milling machines and, more generally, for clamping mechanical parts with complex geometries.

Clamping Squares with T-slots and G25 Cast Iron

Among the various clamping systems for machine tools, the squares can be dimensionally customised and supplied with T-slots from 14 to 28 mm as per the DIN 650 table, with H7 and H12 tolerances.

The material used for this product is G25 cast iron with a lamellar structure which, unlike electro-welded steel, absorbs the vibrations generated by the chip-removal process. This minimises the negative effects on both the machined surfaces (vibration during milling) and the structural integrity of the machine tool.

For large clamping squares, several pieces can be combined to form the required size. This precision angle plate is highly versatile, as the modularity of the structure allows multiple types of set-up.

As an alternative to our standard precision mechanics products shown in the catalogue, G.Bonanomi can manufacture any size, as well as custom clamping elements, using any material, to best meet the needs and requirements of the end customer.

Sizes of the clamping squares

Our clamping squares are available in the Express Shop: select the size you need and wait for our formal quote.

Currently available:

• Clamping square 2000x800x850
• Clamping square 300x300x250
• Clamping square 250x250x200
• Clamping square 200x200x150
• Clamping square 300x350x160
• Clamping square 1000x700x600
• Clamping square 500x500x400
• Clamping square 400x400x300
• Clamping square 400x320x400

Not only Clamping Squares: discover other Bonanomi Products

In Bonanomi, we develop a wide range of mechanical processes for our customers.

In our Precision Mechanical Workshop, we also manufacture:

• Cubes and Clamping Towers
• Surface Plates 
• Dressing Plates
• Blocks and Control Cylinders 
• Clamping Plates
• Support and Levelling Columns 
• Parallel Boxes
• Control Rules 
• Test Benches 

We also offer Third Parties Mechanical Processing (Outsourcing Services).

Frequently asked questions

What are clamping systems for machine tools?

They are the elements that lock and position the workpiece on the machine table during machining. Clamping squares are part of this family: they provide a vertical plane orthogonal to the base on which to fix the workpiece, so that several faces can be reached with a single set-up.

What is the difference between T-slots and zero point?

T-slots (14 to 28 mm, DIN 650) let you fix clamps and brackets at any point on the plane, for maximum versatility. The zero point version works on zero-point references and is designed for fast, repeatable workpiece changes, typical of CNC machining.

Why are clamping squares made of G25 cast iron and not steel?

G25 cast iron with a lamellar structure absorbs the vibrations of chip removal far better than electro-welded steel. This reduces vibration during milling, improves surface finish and preserves the integrity of the machine tool.

Can clamping squares be made to measure?

Yes. In addition to standard models available for prompt delivery, we manufacture clamping squares and clamping elements to measure, in any size and material, even starting from the customer's drawing.

What accuracy do Bonanomi cast iron squares guarantee?

The squareness between the vertical plane and the base complies with DIN 875, which sets the maximum permissible deviations. The squares can be supplied ground for dimensional-control applications.

All Sizes