It is very important to select the correct die before cutting the material for a job. If the incorrect die is selected then the bend will be distorted, mark the surface of the material or fail to fit the material due to the incorrect profile.
Match Die Type to the Profile
Round-groove dies are generally best suited to solid bars and rods and allow the material to be seated fully within the die channel for the full bend length. V-dies are generally best for flat bars and sections where even load distribution is key. Wiper dies are often used when very close to a feature or end of a workpiece.
Check Throat Depth Against Your Profile Size
The Throat Depth of the Die must be sufficient to allow the highest point of the profile to enter the Die by several mm. A short Throat Depth causes the workpiece to lift and twist.
Consider Die Width and the Resulting Radius
A wider opening die produces a gentler radius than a narrower die opening. The required inside radius has to be worked out from the die width. For this reason, many fabricators using Euromac Bending Machines keep a small set of different die widths on hand.
Match Die Material Hardness to the Workpiece
The softer materials such as nylon die or bronze die will mark less on stainless steel and aluminium but will wear faster on the harder steel alloys. For the softer alloys a hardened tool steel die is not necessary and in fact would mark the surface of the alloy, a nylon or bronze insert in the die can be used to protect the surface of the alloy.
Factor in Die Geometry
The die contact faces need to be of the correct shape to produce a good quality bend and smooth surface. It is worth reading up on the subject of die geometry before setting up to produce an unfamiliar profile as small changes in contact angle can result in a kinked bend.
More on Euromac Bending Machines can be found at https://www.cotswold-machinery-sales.co.uk/euromac-bending-machines/horizontal-bending-machines/.
By verifying these simple points before commencing a job, reject rates are kept to a minimum and tooling life maximised.
