- 6 -
• Paper stock Unless treated with flame retardant
• Silver & other prec. Metals Highly Reflective
Localized Hardening – Due to the intense heat associated with laser cutting, the edges of the
material can become hardened. This area is referred to as the Heat Affected Zone (HAZ). This is
especially important for secondary operations such as reaming and tapping. The HAZ increases
in thicker materials.
Hole diameter – The entry diameter is larger than the exit diameter, creating a slightly tapered
hole. Minimum hole sizes are related to stock thicknesses and can be as low as 20% of the stock
thickness.
Turret Press Basics
CNC Turret presses are particularly suited for low to medium quantity production runs. By
utilizing “soft tooling” or standard tooling, turrets lend themselves to both the highly flexible
production of prototypes and inexpensive production quantities.
Tolerances – The feature to feature tolerance for the turret press is +/-.004”, the punched hole
tolerance is +/-.002”. When dimensioning for the turret, select meaningful datum in the body of
the part—passing through hole centers, if possible—rather than using an edge or corner of the
part. Edges can be tapered or misaligned and result in enough variance to be dimensionally
uncertain. Furthermore, the use of meaningful datum facilitates inspection.
Special forms – The turret punch press offers many versatile solutions for putting special
features into a flat sheet. Some of the options are counter sinks, offsets, card guides, embosses,
draws, wipe forms, part markings, lettering, lances, half-shears, and weld projections. Virtually
any form can be made as long as it falls within the following constraints. The form depth must be
less than 5/16" and it must fit into a 3.5" diameter circle. Progressive tools can also be made for
the turret press. These tools can punch and form small parts as efficiently as a progressive punch
press tool with a lower initial cost.
Hole to edge clearance – A good rule of thumb for hole placement is to keep the hole at least
one material thickness away from any edge. If the hole gets too close to an edge a bulge can
form as shown below. Also note, if the hole is used for fastening two pieces together, extra web