TOLERANCES & GUIDELINES FOR ASSEMBLIES

 

* STANDARD LENGTH TOLERANCES FOR
CABLE ASSEMBLIES AND CUT-LENGTH CABLE		 * OUTSIDE-DIAMETER TOLERANCES FOR
PLASTIC COATED CABLE
Liberal tolerances allow a faster rate of production and lower cost. The "standard" tolerances shown in the chart normally permit a cost saving over "close" tolerances. Tolerances closer than those shown can be supplied at a higher cost upon (1) reviewing your specific requirements and (2) mutual agreement regarding methods of inspection.

Length in Feet
Tolerance in Inches Standard
0-5
5-10
10-20
±1/8
±3/16
±1/4
20-40
40-60
60-90
±3/8
±1/2
± 1
90-200
Over 200
± 2
± 4


* CABLE DIAMETER RELATED TO PULLEY OR SHEAVE DIAMETER
Cable or wire rope will give increased service if (1) it operates over the largest possible pulley or sheave diameter and (2) it is properly supported in the pulley or sheave groove. Working life of the individual wire strands is greatly reduced as the pulley or sheave diameter is diminished. The chart shows minimum tread diameters over which various sizes and constructions of cable should operate.

When designing a pulley groove, the groove should be 150% of the maximum tolerance of the wire rope.
* EXAMPLE:
A 1/8" 7 x 19 aircraft cable has a minimum tolerance of .014" (.125 minimum, .139 maximum). Multiplying the .014" maximum tolerance by 150% = .021". Adding .021" to 139" maximum diameter = .160" which should be the pulley groove dimension.
Inner
Cable Diameter
in Inches
Coated to
Outside-Diameter
in Inches
Standard
Tolerance
Of O.D. in Inches
3/64 to 1/8
up to 1/4 max.
± .007
5/32 to 1/4
up to 3/8 max
± .010
9/32 to 3/8
up to 1/2 max
± .015
7/16 to 1/2
up to 3/4 max.
± .020

MINIMUM TREAD DIAMETER
FOR PULLEYS OR SHEAVES
Ratio of cable diameter to pulley diameter:
42:1
24:1
12:1
28:1
18:1
Desirable Minimum in Inches / Critical Minimum in Inches
Cable
Diameter In Inches
6 x 7
or
7 x 7
6 x 19
or
7 x 19
6 x 31
7 x 31
6 x 37
6 x 7
or
7 x 7
6 x 19
or
7 x 19
1/16
3/32
1/8
2-5/8
2-15/16
5-1/4
-
2-1/4
3
-
-
-
-
1-11/16
2-1/4
-
-
-
5/32
3/16
7/32
6-9/16
7-7/8
9-3/16
3-3/4
4-1/2
5-1/4

-
-
-

2-7/8
3-3/8
4
-
-
-
1/4
5/16
3/8
10-1/2
13-1/8
15-3/4
6
7-1/2
9
3
3-3/4
4-1/2
4-1/2
5-5/8
6-3/4
2-1/2
3-1/8
3-3/4
7/16
1/2
18-3/8
21
10-1/2
12
5-1/4
6
7-7/8
9
4-3/8
5

When designing aircraft control cable systems, minimum ratio of cable diameter to pulley diameter is 35:1.
Pre-stretched aircraft cable, both stainless steel and galvanized, are available in 1/16 ", 3/32" and 1/8" diameter at 10% added charge.

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wire rope, MiI-W-871 61. September 1982 Wire Strand. Non-Flexible