Engineering and Tolerance

Stock Spring Tolerances and Engineering Notes

Imperial/Metric Conversions

Force
To Convert Newtons to Kilogrammes Pounds
Multiply by 0.102 0.22487
To Convert Kilogrammes to Newtons Pounds
Multiply by 9.807 2.2046
To Convert Pounds to Newtons Kilogrammes
Multiply by 4.448 0.4536
Rate
To Convert kg/mm to lb/in N/mm
Multiply by 55.998 9.807
To Convert lb/in to kg/mm N/mm
Multiply by 0.017858 0.175133
To Convert N/mm to kg/mm lb/in
Multiply by 0.101968 5.7099
Length
To Convert Inches to Meters Feet Millimetres
Multiply by 0.0254 0.08333 25.4
To Convert Millimetres to Meters Feet Inches
Multiply by 0.001 0.003281 0.0393701

Stock Compression Spring and Extension Spring Engineering Notes and Tolerances

Direction of Wind

Left or Right at Lee Spring’s Descretion

Compression Spring Ends

  • Squared and ground (squareness within 3°:Standard Springs (LC, LCM), Heavy Duty Springs (LHC)
  • Squared, Not Ground: Bantam Mini Compression Springs (CB), Instrument Springs (CI, CIM), Lite Pressure Springs (LP)

Extension Spring Ends

  • Full diameter at random position, except those LEM suffix products designed to meet DIN 2097 Standards
  • Loop openings are approximately one wire diameter.

Stock Compression Spring and Extension Spring Tolerances

Compression and Extension Outside Diameter (OD) Tolerances

Imperial/Inch
0.025" - .040” ± .001”
.057” - .094” ± .003”
.102” - .250” + .003”–.005”
.300” - .500” ± .008”
.540” - .850” ± .015”
.875” - 1.125” ± .020”
1.150” - 1.218” ± .025”
1.250” - 1.460” ± .030”
1.480” - 1.687” ± .040”
1.937” - 2.000” ± .055”
Metric
0.64mm - 1.02mm ± .03mm
1.45mm - 2.36mm ± .08mm
2.59mm - 6.10mm + .08mm – .13mm
7.62mm - 12.70mm ± .20mm
13.97mm - 21.59mm ± .38mm
22.23mm - 28.58mm ± .51mm
29.21mm - 30.94mm ± .64mm
31.75mm - 37.08mm ± .76mm
37.59mm - 42.85mm ± 1.02mm
49.20mm - 50.80mm ± 1.40mm

Spring Rate Tolerance: ± 10%; Solid Height Tolerance : + 5%, no lower limit

Stock Torsion Engineering Notes and Tolerances

General Notes

  1. Lengths of legs are shown as "A" in sketches below.
  2. Please note: "R" (radius in inches) where force is applied is always 1/2 of "A" (Length of Leg).
    Dotted lines of legs show loaded position where values of "T" (Torque) will be achieved at "R" (Radius).
  3. To translate torque values to direct load:
                    Use Formula - P = T/R
                    P = Load applied at Radius (R)
                    T = Torque
                    Example: Part LTL 012A 01, what is the load where R = .187?
                    Using P = T/R = .050/.187 = .267lbs.
  4. To calculate torque values other than those listed (Position of Ends), a direct proportion may be used.
                    Example: Part LTL 012 A 01. Torque shown in catalogue listing is .050 in-lbs. for 90° deflection;
                    therefore, torque for 45° would be .025 in-lbs.
  5. Inspection of Load - Loads should always be checked at the Radius ("R" value)
  6. Mandrel Size: Generally, torsion springs are used over a mandrel (shaft or arbor). The column "Suggested Mandrel Size,
    Inches", allows approximately a 10% clearance for the various deflections shown in examples below. If you require greater
    deflections, we suggest a suitable reduction in the mandrel size.
  7. Direction of Wind: Good design dictates that torsion springs should be used in the direction that winds the coil.
    When ordering be sure to choose either LTL (Left Hand Wound) or LTR (Right Hand Wound) for required application.

Stock Torsion Spring Tolerances

Torque: ± 10%
Tolerances on Free Position:
From 3 to 10 total coils (Incl.) ± 10°
From 11 to 20 total coils (Incl.) ± 15°

Tolerances on Outside Diameter

Inches
0.093” - .125” ± .004”
.126” - .200” ± .005”
.201” - .300” ± .007”
.301” - .410” ± .010”
.411” - .500” ± .013”
.501” - .700” ± .015”
.701” - .875” ± .020”
.876” - 1.125” ± .025”
1.126” - 1.218” ± .030”
1.219” - 1.250” ± .035”
Millimetres
2.36 - 3.17 ± .10mm
3.18 - 5.08 ± .13mm
5.09 - 7.62 + .18mm
7.63 - 10.41 ± .26mm
10.42 - 12.70 ± .33mm
12.71 - 17.78 ± .38mm
17.79 - 22.23 ± .51mm
22.24 - 28.58 ± .64mm
28.59 - 30.94 ± .76mm
30.95 - 31.75 ± .89mm

Stock REDUX Wave Spring Engineering Notes and Tolerances

General Notes

  1. Stock REDUX Wave Springs are made of material 17-7PH Stainless Steel
  2. Maximum operating temperature is 650 degrees F
  3. Nominal Load is the approximate force at the Working Height.  Be advised springs may take a set if compressed below
    the Working Height.
  4. The Number of Turns comprises a continuous coil; there is no welding or adhesive between waves.
  5. Ends turns are regular & wavy.  Flat & shim ends can be offered in a special order.

Stock REDUX Wave Spring Tolerances

Rate: ± 25%

The Outside Diameter and Inside Diameter are reference only. REDUX Wave Springs are manufactured to operate with the specified mating Hole Diameter and Rod Diameter.

Lee Spring Part PDF

https://www.leespring.in/sites/leespring/files/part_number_pdf/GuideLeeSpringPartNumbers2012_0.pdf