CASING
Steel casing is used for borehole strengthening wells and assurance of normal operation of oil pipelines. Casing undergoes hardening treatment which makes it possible to improve in the strength, resistance to corrosion and deformation characteristics. Casing pipes protect wells from flooding with underground waters and seepage of gas. Steel casing balance pressure in different rock layers ensuring normal circulation of bore hole fluid and protection of the entire well system.
GOST 31446-2017
Steel grade: H40, J55, K55, M65, N80 type 1, N80 type Q, L80 type 1, R95, C90, T95, C110, P110, Q125, Q135.

Requirement level: PSL-1, PSL-2, PSL-3.

Thread type:
  • LС (short thread);
  • SC (long thread);
  • BC (shouldered buttress-thread coupling);
  • ОТТМ (buttress-thread coupling);
  • ОТТГ (buttress-thread coupling with metal-to-metal seal assembly).

P – plain end, S – short rounded thread, L – long rounded thread, B – buttress thread
GOST 633-80
Steel grade: Д, К, Е, Л, М, Р.

Type of thread connection: ОТТМ, ОТТГ and V-thread.
API 5CT
Steel grade: H40, J55, K55, M65, N80 type 1, N80 type Q, L80 type 1, R95, C90, T95, C110, P110, Q125, Q135.

Type of thread connection:
  • SC (short thread);
  • LC(long thread);
  • BC (shouldered buttress-thread coupling).


P – plain end, S – short rounded thread, L – long rounded thread, B – buttress thread