The hardness of the gear tooth surface allows us to separate the product into soft tooth gear and hard tooth surface gear; however, what distinguishes them and how should we decide?
1. The bearing capacity of the tooth surface should be correlated with its hardness; so, the bearing capacity increases with increasing tooth surface hardness.
2. Hard-flanking gearsHBS 350; soft gears
3. The soft gear is carefully chosen; the hard gear is straightforward to create.
4. Common gear failure including tooth surface pitting, tooth root fatigue fracture, etc. is associated with gear hardness and quality.
5. Hard tooth surface gears usually refer to heat-treated; soft tooth surface gears are usually not heat-treated. Because there is no heat treatment procedure, the soft tooth surface is quite reasonably affordable.
6. The hardness may be raised by means of 6,20Cr‐20CrMnTi‐20CrMnVB‐20CrNiHCarburizing quenching heat treatment.
7. Higher hardness may be obtained by nitriding process from 7.38CrMnAl.
8. To increase hardness, 40Cr, 45#, 45Mn2 steel may be treated with final heat treatment, high-frequency tempering or nitriding treatment.
9. Usually after heat treatment, the soft gear is the gear blank; the final product is cut after cutting. Usually scoring 8 grades, the precision in delicate cutting might reach 7 levels.
10. The soft tooth surface gear is simple to manufacture, economical, high productivity, and good running performance; it is mostly used in general machinery without tight control on transmission size and weight, as well as small production. Its bearing capacity is low.
11. The hard tooth surface gear is quenched, surface quenched or carburizing quenched after the gear is finely cut to increase the hardness. Its bearing capacity is high. Widely used, the hard tooth surface transmission has great load, wear resistance, extended service life, and strength.
12. Usually, the hardness of the tooth surface of the tiny wheel is 30-50HBC greater than that of the big wheel, thereby enabling the working life of the large and small gears to be about equal.
13. You are better off selecting a hard tooth surface gear if the hardness of the product will have a significant impact on the performance of the transmission system; else, you can use soft gears for instruments with low power, strength and precision requirements, and medium and low speed transmission. Welcome to consult; our engineers can kindly answer a variety of queries for you.