• DIAMOND GROOVE, TYPE "DG" - TECHNICAL INFORMATION

TECHNICAL DATA

The DG, Diamond Groove, features a special knurl which makes it superior in holding strength.

STANDARD SIZES:
Standard sizes in a given I.D. range are sizes listed in the decimal equivalent chart either as a fraction, number or letter size. Any other decimal or millimeter size within a given range is considered special and will be priced accordingly.

COUNTERBORE:
Bushings with small holes are counterbored leaving correct drill bearing, to facilitate chip removal and lubrication.

NO COUNTERBORE:
Bushings normally counterbored may be ordered without counterbore by specifying "No Counterbore" or using abbreviation "N CB." (Priced as specials.)

RADIUS:
All bushings feature a blended radius at drill entrance unless other wise specified.

LEAD:
Ground bushings have a concentric ground lead.

STEEL:
Our bushings are manufactured from selected steels known for their long wear and stability. Bushings are also available from other materials at extra cost (bronze, M-2, D-2, stainless steel, etc.)

HARDNESS:
Rockwell C 62 - 64 in the hole.

GROOVE INFORMATION:

APPLICATION DATA:
Castable bushings are made for potted, cast in place or imbedment in jigs made of laminated glass fibers, potting compounds, castable and soft materials. All three basic types DG, Diamond Groove, SG, Serrata Groove, and SP, Serrata Press offer exceptional self-locking grip and holding power.
The DG, Diamond Groove, features a special knurl which makes it superior in holding strength.
The SP, Serrata Press, features a special serration which allows the bushing to be easily pressed into a jig made of plastic or soft materials and offers excellent holding strength.
The SP, Press, features a special serration and a finish ground O.D., outside diameter, which makes it superior for press-in installation in soft materials, such as magnesium, aluminum, masonite, or wood.
* Points to consider when selecting a castable bushing suited for a particular application:
1. Type of material and its hardness or ductility, and groove sensitivity.
2. Maximum load to be transferred onto the bushing.

INSTALLATION DATA:
To maintain accuracy in the production operation, extra care must be taken in mounting hole preparation. Factors to consider are diametral interference fits, alignment, chip clearance and proximity of bushing to work piece.
Diamond and/or Serrata Groove bushings which are located in the mold prior to the molding operation need special attention regarding centerline perpendicularity. Also beware of molding materials in the bushing I.D., inside diameter.
Serrata Groove and/or Serrata Press bushings can be used in drilled holes in imbedment or soft materials. Pilot hole size will vary according to ductility or hardness of the material which bushings will be installed into. Due to the variations in materials used specific pilot hole size recommendations cannot be made.
* Points to consider regarding pilot hole preparation:
1 .Sufficient interference is necessary to assure a firm hold of the bushing. However, excessive interference may crack or distort the jig or fixture because of the displaced material.
2. Heating plastic materials during bushing installation expands the hole which allows easy insertion. Due to shrinkage of the plastic during cooling, the material flows around the serrations providing a shrink fit.

NOTE:
Chip clearance: Due to the abrasive action of metal particles, sufficient clearance should be provided between the drill bushing and the workplace to allow for removal of chips. Careful consideration of this point will aid in producing accurate holes. (A rule of thumb Is, the greater the clearance the greater chance of error.)
Example: The recommended chip clearance for metal producing small chips, such as cast iron, equals one-half the drill diameter. The recommended chip clearance for metals producing long chips, such as cold-rolled steel, equals one to one and one-half times the drill diameter.