Steel Balls for Industrial Equipment — Heavy-Duty Conveyor, Mining & Crusher

API 11AX ball and seat are the critical sealing pair inside a subsurface sucker rod pump. The ball lifts off the seat on the up-stroke to let fluid enter, then seals on the down-stroke to push fluid upward. API 11AX is the API specification that defines their dimensions, materials, and performance.

Common materials include 9Cr18Mo and 6Cr18Mo stainless steel, cobalt-chromium-tungsten alloy (Stellite), YG8/YG13 tungsten carbide, titanium carbide-based hard alloy, and non-magnetic nickel-based alloy. Selection depends on well fluid, sand content, temperature, and pressure.

V11 and V13 are API 11AX valve series with different dimensional envelopes. V11 covers common pump sizes from V11-106 to V11-275. V13 is a larger, heavier-duty series for higher-volume or deeper wells. Both can be supplied in matching sets with material selected for well conditions.

Our balls achieve sphericity within ±2 µm, surface roughness Ra 0.025 µm, and pass 100% vacuum seal testing at 85 kPa for 5–12 seconds. Seats are machined to drawing with OD Ra 1.6, end-face Ra 0.4–0.8, and sealing-line Ra 0.2.

Yes. You can send your drawing, and we can evaluate custom API 11AX ball and seat production based on your size, material, hardness, precision, and surface requirements. We will review the details and confirm whether your specification can be made.

For general service, 9Cr18Mo at HRC 55–60 is standard. For sandy or abrasive wells, choose YG8/YG13 tungsten carbide (HRA 88–92) or Stellite (HRC 40–50). For corrosive low-abrasion wells, 6Cr18Mo or non-magnetic nickel-based alloys work well. We recommend based on your well fluid analysis.