1.)material :40Cr or other

2.)standard: API SPEC11B

3.)Feature:

 1.Coat Thickness( in ): 0.01in-0.02in  

2. Surface hardness: HRC56-62

    Basic hardness:HRA56-62

 3.Life: > 180days

4.Min. Tensile Strength: 655 Mpa

5. phosphorylate or not (according to demand)

4.) Hole rate: <2%

ShouGuang XinDa Petroleum Machine Accessories Co., Ltd, founded in 1999, is a professional manufacturer of API 11B sucker rod couplings, including Spray Metal coupling, class T coupling, Altra High Strength,Sub OD coupling, with various spec. of Full size, Slim Hole, grand chamfer, Two-way chamfer, etc. With world top level equipments and technicians, the monthly production capacity is more than 30,000pcs. All of our products are excellent in quality and low in price, which satisfied many of our customers home and overseas.