How do you choose between a hard-toothed-surface worm gear reducer and a soft-toothed-surface worm gear reducer, and what are the key differences?

I’m sure everyone is familiar with gear reducers. So, what exactly is a hardened‑tooth‑surface reducer, and what is a soft‑tooth‑surface reducer? How should you choose when purchasing a reducer? Below, we’ll explain the differences between hardened‑tooth‑surface and soft‑tooth‑surface reducers, as well as how to make the right selection. Hardened‑tooth‑surface reducer

The primary difference between a machine‑type reducer and a soft‑tooth‑surface reducer lies in the hardness of the gear tooth surface: the higher the tooth‑surface hardness, the greater its load‑carrying capacity. Depending on the hardness‑testing method, hardness can be classified into three types: scratch hardness, indentation hardness, and rebound hardness.

1. Scratch hardness is primarily used to compare the relative hardness of different minerals. The method involves using a rod with one end hard and the other soft; the material being tested is scratched along the rod, and its hardness is determined by the length of the resulting scratch. Qualitatively, scratches on harder materials are longer, whereas those on softer materials are shorter. 2.

Indentation hardness is primarily used for metallic materials. In this method, a specified indenter is pressed into the material under a given load, and the material’s hardness is determined by comparing the extent of localized plastic deformation on its surface. Depending on variations in the indenter type, applied load, and loading duration, several indentation hardness tests exist, including Brinell, Rockwell, Vickers, and microhardness tests. 3. Rebound hardness is also mainly applied to metallic materials. This method involves dropping a specially designed small hammer from a fixed height onto the test specimen; the material’s hardness is then assessed based on the amount of strain energy stored (and subsequently released) during the impact, as measured by the rebound height of the hammer.

Since the hardness of gear surfaces in gear reducers is closely related to their load-carrying capacity, the Brinell hardness test using an indenter is typically employed to measure surface hardness. Gear surfaces with a hardness exceeding 350 HBS are classified as hard‑tooth surfaces, whereas those with a hardness of 350 HBS or lower are designated as soft‑tooth surfaces. This fundamental distinction defines the difference between hard‑tooth and soft‑tooth gear reducers.

That concludes the most straightforward overview of the differences between hard-tooth‑surface gear reducers and soft-tooth‑surface gear reducers. Based on this explanation, you should now have a solid understanding of both types and a clear sense of how to choose between them, enabling you to make an informed decision that best suits your specific needs.