What sizes can KTH Holts handle ?

We have a crane capacity of up to five tonnes but we also handle components weighing a fraction of a gramme.

Obviously we do not process a component weighing a few tonnes in the same furnace as those weighing a fraction of a gramme. It all depends on the treatment process, geometry and weight.

Please contact us for treatment specific capacities & facilities.

How do I define my heat treatment requirements ?

Download our editable PDF file to take you through the details we need to quote quickly and efficiently.

What is the difference between ? What does this term mean ?

Use our dictionary to understand common heat treatment terms.

Why stress relieve / anneal / normalise  ?

When metal cools from its manufacturing temperatures it locks in stress from the different cooling rates between surface and centre. It may also be rolled, forged or simply shrink from cooling after casting. Nor   will the material be uniform because of then different thermal history across the section of the metal.

Machining will release stress and unbalanced stress results in distortion. Heating above the last processing temperature will also release stressed.

The family of thermal cycles of stress relieving, annealing & normalising are used to counter these effects and provide as a stable & uniform product as possible for further manufacturing procedures or use in service.

What is the difference between Total Case Depth & Effective Case Depth  ?

Effective case depth is defined by a cut off point at a given hardness along the hardness gradient between the surface and the code of the steel. The effective case depth is the region in which enhanced material performance can be sustained.

Total case depth is the complete region that has been affected by the hardening process. It is measured down to the point where the material’s inherent core hardness takes over. Total case depth extends past the cut off point of effective case depth but includes the areas where hardness has been increased by only one or two points which generates little if any enhancements in performance.

Effective case depth takes longer process times to achieve and therefore costs more but delivers a significantly longer working life. Make sure you specify which one you need.

Which steels are best for   ?

Popular Carburing Grades

EN32b / 08A15

EN34 /655M17

EN36 / 655M13

Popular Through Hardening Grades

EN24 / 817M40

EN26 / 826M40

Popular Nitriding Grades

EN19/ 709m40

EN24 / 817m40

EN40 B/ 722M24

EN41 / 905M31

Popular Flame / Induction Hardening Grades

EN19 / 709m40

EN24 /817m40

EN8D / 080M40