Differences between spring material??

[hk300]

Can anyone explain the differences between the material that is used for springs?

Chrome Silicone
Chrome Vanadium
Chrome Manganese
Titanium
... cheap springs on ebay...

I guess that the used material determines significantly the price of the springs, but how to grade the above materials? In terms of longlasting, durability, strength?

[Jakub]

The obvious difference based on theyre names gives the major alloying elements (vanadium, manganese, silicon). Although it is probably the case that all 3 steels have all of these elements in their breakdown, its just the higher element takes the naming of the steel. Even so the maximum % by weight that would be expected of the alloying elemts would be no more than around 1-2%.

Chrome Vanadium Steel, 61XX steels, is a propular and well known material for springs, used for many years.

Chrome Silicon Steel, 92XX series (also used for manganese series), can be used for higher stressed springs as it has higher strength properties. It is therefore a stronger, longer lasting material than the vanadium steel.

Im not to familiar with manganese alloy steels used for springs, but generally in steel alloying, manganese can have a higher influence on material hardness and strength than silicon (can be used to produce harder materials).

Titianium is an entirely different material. Its density (and therefore weight) is around half that of steel, although its stiffness is approximatly half as well (giving a specific stiffness which is just slightly better that steel). For springs there are specific grades of titanium that can be used for springs.
In the design of a spring, much less material can be used for a titanium spring, hence a fairly large weight saving can be found by using this material (in the order of more than half the weight of a steel spring). Although expect cost to be more than for steel springs. Personally I would still be tempted to use steel for fatigue and long lasting.

Regards

Jakub
jakub@whiteline.com.au