There are 14 Steel/Cast-Iron and Heat-Treatment categories, each with 3 Quality levels (ML, MQ, ME) - identical to the ISO 6336-5 standard for Gears.

Steels Categories and Heat-Treatment - see Example steels of each Steel Category.

1.Normalized, Low-Carbon Wrought-Steelsa - St

2.Normalized, Low-Carbon, Cast-Steelsa  - St(cast)

3.Black Malleable Cast-Iron - GTS (perl)

4.Nodular Spheroidal Cast-Iron - GGG ( e.g. in image above )

5.Grey Cast-Iron - GGG

6.Through-Hardened Wrought Carbon-Steelsb - V

7.Through-Hardened Wrought Alloy-Steelsb - V

8.Through-Hardened Cast Carbon-Steel - V(cast)

9.Through-Hardened Cast Alloy-Steel - V(cast)

10.Case-Hardened Wrought-Steelsc - Eh

11.Flame or Induction-Hardened Wrought or Cast-Steels (IF)

12.Nitrided Wrought-Steelsd - NT(nitr)

13.Through-Hardened Nitrided-Steelsb - NV(nitr)

14.Through-Hardened Nitro-Carburized Wrought-Steele - (NV (nitr-car)

a - ISO 4948-2 (ISO10020) Part 2 - Classification of unalloyed and alloy steels according to main quality classes and main property or application

b - ISO 683-1&2:2016 - Heat-treated Steels, alloy steels and free-cutting steel Part 1 Non-alloy ... , Part 2 Alloy steels for quenching and tempering

c - ISO 683-3:2022- Heat-treated Steels, alloy steels and free-cutting steel Part 3 - Case-hardening steels

d - ISO 683-5:2017 - Heat-treated Steels, alloy steels and free-cutting steel Part 5 - Nitriding Steels

e - ISO 683-1, ISO683-10, or ISO 683-11

Steel Quality

The Steel Quality Standards are:

ML - Modest demands on the material quality and the heat treatment process.

MQ - Material Quality and Heat-Treatment standards met by experienced manufacturer.

ME - High degree of reliability of Material Quality and Heat-Treatment process.

The requirements to be met for different steel qualities include: Chemical Analysis, Melting Practice, Surface Crack Detection after machining, and Hardness. Sometimes, to confirm the analysis a test piece is prepared and heat-treated together with cam - See ISO 6336-5.

Enter a Hardness value in the HB, HV, or HRC hardness scale - see image above

The default Hardness is the average of the Upper and Lower Hardness Limits

The Hardness you enter must be within the Upper Hardness Limit and Lower Hardness Limit. The limits are specified in ISO 6336-5.

Lower H Limit ≤ Actual Hardness (HB, HV, HRC) ≤ Upper H Limit

In the example above, you can enter a Hardness in the range of 175-300HB, 178-315HV, or 9-32HRC.

When you enter a Hardness value under one of the Hardness Scales, the other two Hardness Scales update automatically.

The Orange Separator indicates the Flank, Steel Category, Steel Quality, Heat-Treatment Type and/or Steel-Type with Steel Acronym are indicated in the separator.

E.G:  Inner Flank: 004 ML Nodular / Ductile / Spherical Cast Iron (GGG) 

Flank : Inner

Steel Category : 004

Steel Quality : ML

Steel Name : Nodular / Ductile / Spherical Cast Iron

Steel Acronym : GGG

The Results are:

Maximum Contact Stress (MPa - Mega-Pascals)

When you select the Follower-Roller - see Roller-Life tab - we can use the contact-force, the combined geometry, and the combined materials of the Cam and the Follower-Roller to calculate the maximum contact-stress.

Note - Optimized Roller Profile

Many Follower-Roller manufacturers have three options for the external profile of the Follower-Roller: cylindrical, constant radius (e.g. R=500 mm) , or an “optimized” profile. We do not know the exact shape of the “optimized” profile. Therefore, if the Part-Number of the Follower-Roller indicates an “optimized” profile, we assume its profile to have a radius equal to the constant-radius of the other Followers-Rollers with the same external diameter. Thus the contact is assumed to be elliptical. This is a safer than trying to estimate how much lower is the actual contact-stress with an “optimized” profile.

Maximum Dynamic Contact-Stress - (MPa - Mega-Pascals)

Maximum Contact-Stress × Safety Factor - see Parameters tab > Enable Lifetime, Edit Safety-Factor

Maximum Allowable Contact Stress

A property of the Steel-Category, Heat-Treatment, and Steel Quality that you select, together with the Surface Hardness that you enter - see above Cam Materials and Hardness

Dynamic / Allowable, (Z

Ratio of Maximum Dynamic Contact-Stress : Maximum Allowable Contact Stress

We use Z on the plot of Ratio of Dynamic/Allowable (Z) against Number of Cycles (N) - see Z-N plot below. Each Steel Category has a different plot.

Depth of Max Shear Stress (mm)

The Maximum Shear-Stress is below the surface of the Cam-Profile (and Follower-Profile). The Depth of Maximum Shear-Stress is a function of the size and shape of the contact between the Follower-Roller and Cam-Profile.

Recommended - for surface or case hardened cams : Minimum Depth of Surface-Hardness > 2 × Depth of Maximum Shear-Stress.

Line Contact : Depth of Maximum Shear-Stress = 0.78 x Width of Contact

Circular Contact : Depth of Maximum Shear-Stress = 0.48 x Radius of Contact

Elliptical Contact : Depth of Maximum Shear-Stress 048 < Half of minor axis < 0.78

Maximum Shear Stress

Approximately 0.3 x Maximum Contact-Stress

Dynamic Shear-Stress

Maximum Shear-Stress x Safety-Factor - see Parameters tab > Enable Lifetime, Edit Safety-Factor

Cam-Life, N

99% reliability

Minimum - 100,000 cycles

Maximum - 10,000,000,000 cycles (1010 rotations, 10 billion).

Cam-Life, Hrs.

Number of Hours, based on millions of Cam Rotations and Machine Speed (RPM).

Cam-Life, Yrs.

Number of Years, based on 8760 hours per year.

Z (in graph above) = Maximum Dynamic Contact Stress Allowable Contact Stress

Z=1, Cam Lifetime = 1.

1 × Life of Steel Category in Groups 1 : 1.0 × 10^9 cycles

1 × Life of Steel Categories in Group 2: 5.0 × 10^7cycles

1 × Life of Steel Categories in Group 3: 5.0 × 10^6 cycles

1 × Life of Steel Categories in Group 4: 5.0 × 10^6 cycles

Z > 1, Cam Lifetime is reduced

Z < 0.85, Cam Lifetime is infinite (N > 10^10 cycles, 10 billion cycles)

N < 10^5 cycles, fatigue does not apply