This material is obtained by animal leather tanning.
Leather tanning for industrial purposes can usually be:

• VEGETABLE TANNING WITH TANNIN (natural)
• MINERAL TANNING WITH CHROME

By means of tanning with tannin it is possible to get stiff, strong and quite permeable leathers; by means of tanning with chrome it is possible to get soft and firm leathers. Both processing assure resistance to breaking of 3 Kg/mm2 (at least).
Tannin tanning leather trimmings are used for hydraulic seals, operating pressure up to 250 atm. - temperature range between +40°C and +60°C.
Chrome tanning leather trimmings are used for oleo dynamic seals, operating pressure up to 350 atm. - temperature range between +80°C and +100°C.