Precision Investment Casting Texas Precision Metalcraft Ltd. Investment Casting Institute


Design Tolerances

LINEAR DIMENSIONS

(general tolerances are recommended for non-functional areas.)
Finished tolerance
Up to 1" ± .005"
Over 1" ± .005"/" 		General tolerance
Under 2" ± 1/64"
2" - 4" ± 1/32"
4" - 6" ± 3/64"
Over 6" ± 1/16"
Special Requirements on selected dimensions:

Under 0.250" = ± .003"
0.251" to 0.500" = ± .004"


RADII

Small radiuses - minimum of ± 1/64"
Larger radiuses - ± 1/64" for each 2" of radius


STRAIGHTNESS

Normal minimum tolerance
± .005"/" 		Coined or Sized
± .003"/"


Flatness

As Cast
Up to 1" ± .008
1" to 2" ± .016
2" to 4" ± .025
4" to 6" ± .030 		After Straightening
± .004
± .008
± .012
± .015

CONCENTRICITY


 		T.I.R.
O.D.
¾"
1"
1½"
2" 		I.D.
¼"
½"
¾"
1" 		As Cast
± .004"
± .005"
± .008"
± .010" 		Straightened
± .004"
± .005"
± .005"
± .008"

ROUNDNESS

Solid Bars Tubes
O.D.
½"
1"
1½"
2" 		T.I.R.
± .010"
± .016"
± .024"
± .030" 		As Cast
± .010"
± .020"
± .024"
± .030" 		Straightened
± .005"
± .006"
± .008"
± .010"

ANGLES

Supported ± ½ Degree
Unsupported ± 1½ Degrees

ROUNDNESS


 Blind Holes Diameter Through Holes Diameter
Length
1/8"
1/4"
1/2"
3/4"
1"
1 1/4"
1 1/2"
2"
2 1/2" 		Ferrous
__
3/16"
1/4"
1/2"
5/8"
3/4"
3/4"
1"
1" 		Non-
Ferrous
1/8"
3/16"
1/4"
7/32"
3/8"
7/16"
1/2"
9/16"
5/8" 		Ferrous
__
3/32"
1/8"
3/16"
1/4"
5/16"
3/8"
7/16"
1/2" 		Non-
Ferrous
1/32"
3/64"
3/32"
5/32"
7/32"
1/4"
5/16"
3/8"
1/2"