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Bulldog Industrial Holdings Limited

  Call: +44 (0) 161 477 0775 

Stockport,  United Kingdom


Lockforming Machines


The Pittsburgh Lockforming machine can be supplied in a 20's    (5station) or 16's (7 station) option depending on the size of seam required and thickness of material.

The Pittsburgh rolls are fitted between sideplates with the option to fit 1 of 10 cnc machined roll sets to the outboard extention shafts. The 16's Pittsburgh roll set incorporates automatic material gauge compensation to ensure tight definition of the seam throughout the gauge range.



 The Pittsburgh Lock Joint

Two profiles illustrating Pittsburgh and Right Angle Flange profiles before and after seaming - joining two edges at 90 degrees.. 


This system is used as a simple method to join between 0.6 mm and 1.2 mm sheet steel at right angles and is designed to lock rigidly together without the need for a post seaming operation.  When used in conjunction with a button punch autoguide flanging machine it is possible to join a curved edge at right angles to another sheet. The outboard roller tooling set can also be interchanged for 1 of 9 roll sets. The button punch machine has 9 forming stages and is fitted with the female profile between the sideplates and the male "Right Angle Flange" profile outboard. As with the 16's Pittsburgh the female roll set incorporates automatic material gauge compensation to ensure tight seams are formed on thinner materials. The female profile has a pocket depth of 14 mm and uses 35 mm of material.



The Button Punch Joint

Two profiles illustrating the Button Punch joint before and after seaming joining two edges at 90 degrees.  


The Flanging Machine is constructed using hardened working components for wear resistance and blackened plates to protect against corrosion. It is housed in a modern powder coated cabinet allowing easy access during operation. The machine is used to form a right angle flange up to 15 mm high on material between 0.7 and 1.6 mm thick.

A uniform flange can be formed on straight or consistent curved components down to a radius of 60 mm. The outer roll can then pivot up to remove completely formed discs using a simple release lever. The gear connected flanging rolls are driven by a 0.37 Kw motor at a throughput speed of 4 m / min. 

Autoguide Version

An Autoguide version is available which produces a consistent height flange on straight or contoured components by using a spring loaded follower roll and height pin. The spring is adjustable for different gauges and can be locked back to ease product removal.

A button punch head can be added for use with the female profile.


Flanging Attachments

Flanging attachments can be fitted to any of the standard rollformers and are capable of forming 10 mm flanges on products between 0.4 and 1 mm thick.

These mount directly to the top of the forming head picking up drive from it and come as standard with the autoguide feature. A button punch option is available.


A small tool but a useful addition

The button punch snap lock hand tool plier is only a small tool but a worthy addition when hard to reach corners are needed for assembly of joints in sheet metal especially applicable in the production of air ducting and also building flashings when extra punches are needed to ensure rigidity (these useful handtools works in conjunction with our Button punch snap lock roll forming machine and Flangers).