Slug Pulling:Techniques and Tool Options

   Diamond Needle File

Use to notch dies for better slug retention.

.1+ sq. file 200/240 grit.  

Cat No. *A-FTN-121420

                             Slug Pulling is when the material that is suppose to drop out of the die instead sticks to the face of the punch and pulls up out of the die.   This slug can then         

                              drop on top of the sheet. If a punch has the misfortune of striking this slug on a future hit, two types of damage to the punch can occur.  If the punch hits squarely on the pulled slug, it may merely cause the punch to have to pierce through two material thickness into a die with clearance meant for only one material thickness.  The result is heavy edge wear and gauling.  The more damaging occurrence is when only a portion of the face of the punch hits the pulled slug.  This can cause side load pressure in which the punch may shear (scrape) against the dies great wear or edge roll to punch and dies cutting edge.

   Reduce galling, increase tool edge life and improve stripping.  Use with standard tools, forming and cluster (gang) punching. To use, simply spray or wipe this premixed lubricant on every 3-6 sheets placed in press.  CLM-50 Formula is a oil base, so it may be mixed with kerosene to conserve or for easier sheet cleaning when plating is to be performed.  This is best lube for reducing galling on sides of tools, and extending edge life.  If your trying to keep away from an oil base, our Poly-Form™ is a water based soluble polymer lubricant for CNC turret and high-speed punch presses.  It’s an excellent lubricant for soft nonferrous metals such as aluminum, copper & brass and will protect your nonferrous metals from oxidation including galvanized and tin-plate. Clean to work with and doesn’t stain skin, clothing or cause dermatitis.

Sheet Lubricant CLM-50 oil base or  Poly-Form water based

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Tech-Index

 Replacement Slug Ejectors

EJECTOR

HOLE

Square

Cat.Code  Cost

   Round

Cat.Code  Cost

.078 (2,mm)

*AEJ-S2

*AU65 

.109 (3mm)

*AEJ-S3

N/A

.234-.25/6mm

*AEJ-S6

*AU66   

.394 (10mm)

*AEJ-S10

N/A

Common causes of slug pulling

Suggested Solutions

 

        Excessive Die Clearance

Check the die clearance (reference page 4).  To large of clearance, although increases punch life, can greatly increase the likelihood of slug pulling.

 Slug is attaching itself to Punch Face.

 If punch is equipped, add Slug Ejectors.

Punch Face is Magnetized, attracting Slugs.

 Have Tools Demagnetized

  Lubricant on light gage material causes suction between the

Remove lubricant (any oils) on the top of material. lubricate the bottom of sheet instead.

  punch face & slug.

Add Shear (Inverted, Roof Top or Spherical) to punch.  This will kink the slug preventing it from suctioning to face of punch.

 

Change to Slug Trap™ style die.  (reference below)

 

 

 

Add Shear (Inverted, Roof Top, or Spherical) to punch.  This will kink the slug, making the shape hug tightly to the sides of the die wall.

Slug not Adhering to Die Land

Using a sharp edge of a diamond file, add some notches to the edge of the die wall.  (.02-.03 deep, & 30-40º to the die land.)  No burr will be left in the hole of the sheet but it will cause a slight burr to the slug that will help grab onto the die land. 

Punch is not Penetrating a Proper Depth into the Die

Reference page 12 of CE Section 1 booklet for minimum suggested tool sharpening lengths.