Positive Taper

A die where the hole gets larger as the slug passes through. Recommended with small diameters or widths and when punching aluminum to avoid slug packing.

 Punch Life

The length of the punch tip that can be used and reground before discarding the punch.


 CE.s patented family of tool length adjustment form tool holders.

 R.S.P. or RSP

Replaceable Stripper Plate.  Used in AT sta. B and ST 1/2 & 5/8” Drop-In holders.

 Saw Tooth Effect

The latest style of Wilson manufactured large station and some small station guide assemblies. They feature “no tools needed” for adjustment. No shims required.


A programming and punching method where several parts are produced on one sheet and held on the sheet with small tabs. The sheet is then rapped on the floor and the parts are dislodged. A separate shearing operation is not necessary.


A punch that has four spring-loaded, retractable heels used for nibbling and notching. Recommended for manual machines only.

 Slitting Tool

A long narrow rectangular punch and die used to part or separate a sheet or parts of a sheet.

 Slug ejectors

Devices usually installed onto the face of a punch to repel the slug: e.g. solid urethane plugs, rigid nylon tubing.

 Slug pulling

A costly problem in punching that occurs when the slug is pulled back out of  the die because of the vacuum created between the flat surface of the punch and the slug.

 Slug Trap

A  die made with small protrusions on the interior surfaces of the die land that hold the slug and prevent slug pulling. (Wilson calls theirs Slug Hugger; Mate calls theirs Slug Free.)

 Snap- Apart

A punch and guide assembly that uses 1/2” shank punches, and goes directly into the 1-1/4” station without an adapter bushing. The guide snaps off without having to loosen any screws.

 Split Keeper

A  Strippit design of punch and guide assembly for the 1-1/4” station. Uses Split Keeper design 1/2” shank punches. The guide pulls off without tools. An adapter bushing is needed to fit the 1-1/4” stations.

 Standard Shape

There are currently 10 standard shapes:Rectangle, Obround, square, hexagon, octagon, single “D”, Double “D”, Long “D” , equilateral triangle, and Quad “D”.

 Stripper Plate

Removable plate at the bottom of a guide assembly that serves to strip the material off the punches as the punch retracts.

 Stubby Style

Punches made with a very short length of straight on the tip of the punch for strength. (Tip length equals sheet metal thickness plus .050”) Has only .030 sharpening life. This is the best type of punch to use when punching material thicker than the width or diameter of the punch.

 TiN Coating

 Gold in Color

 WT calls Bear Coat

 Titanium nitride coating (Gold in Color) applied to punch tip. This coating brings the surface hardness up to about 74 Rockwell “C” scale.  Ref. Sec.1-p6 for specifics

 TiCN Coating

 Blue-Grey in color

 WT calls Optima coat

Titanium Carbon Nitride coating applied to punch tip.  This coating brings the surface hardness up to about 88 Rockwell “C” scale.  See Coatings in Technical Reference Index


The upper and lower limits of a size specification. Not to be confused with clearance.

 Tool Steel

A steel of elements that can be hardened to achieve tough after heat treating.

 Urethane Spring

Urethane usually gives stronger stripping power than steel springs, but does not function as well in high-speed punching applications because it heats up and loses its strength.

 Wire E.D.M.

A type of machining where a computer-guided wire does the cutting of the hole in the die or other component.



  Auto-Index   A.I.

A machine option that allows programmable indexing (rotating tool to an angle) of a specific turret station.   Amada Machines usually offer Sta.B as A.I., Strippit 3½”sta., Murata D, F, or G


Identifies a punching operation where the slug is kept as the part.

 Constant Clearance  Corners   

Radiuses are added to corners in Rectangle or Square Dies when clearances exceed .018 

    Prevents large corner burrs.   Makes dies stronger, Increases die life.


A” Dimension  measurement of  the largest  dimension across the shape.

This used to find tool Station shape size fits into.


The female part of  the tool that accepts the slug or formed material. This is usually the lower unit, but it could be the upper unit in a special tool.

 Die Clearance     

The amount of space between the punch tip and the hole in the die. This should be expressed in total clearance and not per side. Clearance is determined by the type and thickness of material to be punched.

 Die Land

The thickness of the hole in the die. Also referred to a die life.

 Die Penetration

The depth  that the punch  penetrates the die at the bottom of the stroke.


A term used to describe a  punch or guide assembly of the type that the punch Body “drops in” the guide assembly; ex. Fab ½” and 5/8”. The ½” drop-in assembly accepts all previous styles of ½” shank punches and goes into the 1-1/4” holder. 

 Fab Tooling

What is referred to as tooling for Strippit, Raskin, & Nisshinbo style machines.


 Indicates that a forming operation is done from the top of the sheet and forms down. Usually not done on an NC turret, common on single station machines.

 Forms up

A forming operation idone from the bottom of the sheet and Formed Up.


An undesirable condition where the material buildup adheres to the sides of  the punch  tip. This is the main reason stripping problems.


The sleeve that fits around the punch assembly in small and large stations. On Small stations, it is sometimes used as a stripper, other times as a guide.

 Guide Assembly

Usually refers to  large station holders or drop-In units.


 Heat Treat

Process of hardening steel on punches and dies to achieve optimum toughness and hardness.


 Heavy Duty

A special punch and guide assembly designed for nibbling or punching heavy material.

 Mild Steel

Usually a low carbon steel, approximately 50,000 P.S.I. yield strength.


 Multi Tool


Holders designed to hold many punches. They are used in an Auto-Index station that rotates the holder until the designated punch is in position.

 Negative Taper

A die where the hole gets smaller as the slug passed through (carbon EDM type) or the newer method of burning small areas of negative taper with wire E.D.M.


A  term used to describe a punching operation where less than the full length, width or diameter of the punch tip is used.

 Notcher Stripper


A hardened slip fit, stepped stripper plate used in a Series 80/90 large station guide assembly to avoid punch deflection during nibbling and notching operations.


This is WT trade name of a coating most similar to industry standard TiCN Coating.

 Perforator: Small Diameter punch and guide Assembly  Tool)

A tool that uses a small quill as the punch and is fully guided by the sleeve assembly normally, sizes are .031” to .093”. This tool is sometimes referred to as the Perforator Tool, and is used in applications where the material is thicker than the diameter of the punch.