Material selection for downhole service
The following material families and grades are references for drawing-led manufacturing discussions. Suitability depends on the specified grade, condition and operating environment.
Alloy Steel
Reference grades: AISI 4140, 4145 and 4340
Appropriate heat treatment can provide different combinations of strength, hardness and toughness.
Typical applications: Shafts, splined components, connectors, transmission components, load-bearing structural parts and custom downhole tool parts.
Selection considerations: Confirm material standards, supply condition, heat treatment, hardness, impact toughness and dimensional requirements.
Stainless Steel
Reference grades: 304/304L, 316/316L, 410 and 17-4 PH
Corrosion resistance, strength, hardness and heat-treatment response vary by grade.
Typical applications: Valve components, sleeves, connectors, precision shafts and selected corrosion-resistant structural parts.
Selection considerations: Not all stainless steels are suitable for H₂S-containing downhole environments. Confirm the medium, temperature, strength requirements and applicable standards.
Duplex Stainless Steel
Reference grades: 2205 and 2507
Selected grades combine high strength with resistance to pitting and crevice corrosion. Performance depends on the grade and operating environment.
Typical applications: Selected corrosion-resistant fittings, valve body components and fluid-contact parts.
Selection considerations: Assess specific service conditions, including high chloride concentrations, elevated temperatures or sulfur-containing environments.
Nickel-Based Alloys
Reference grades: Inconel 625 and Inconel 718
Selected grades offer corrosion resistance or high-temperature mechanical properties, depending on the grade and material condition.
Typical applications: Fasteners for special operating conditions, precision parts and selected high-temperature and high-pressure tool components.
Selection considerations: Confirm material condition, tooling and machining process, heat treatment and inspection requirements. Material cost and processing complexity can be relatively high.
Cemented Carbide (Tungsten Carbide)
Reference grades: WC-Co and WC-Ni systems
High hardness and wear-resistance potential; toughness and corrosion resistance depend on the grade and binder phase.
Typical applications: Wear-resistant inserts, flow-control components, wear-resistant sleeves, sealing mating parts and custom-shaped wear-resistant components.
Selection considerations: Confirm grade, hardness, toughness, dimensions, tolerances and any EDM or grinding requirements.
Titanium Alloys
Reference grades: Ti-6Al-4V (Grade 5)
High specific strength. Corrosion resistance depends on the medium and specific operating conditions.
Typical applications: Custom parts with particular requirements for weight, strength or exposure to specified corrosive environments.
Selection considerations: Evaluate frictional wear, working medium, connection method and machining-deformation risk.
Other optional construction materials
| Material category | Typical application areas |
|---|---|
| Carbon Steel | General structural parts, fasteners and parts without special corrosive service conditions. |
| Martensitic Stainless Steel | Parts requiring strength, hardness or a defined level of corrosion resistance. |
| Copper Alloys | Selected bushings, bearings and special-function components. |
| Engineering Plastics | Insulation parts, guides, bushings and selected sealing auxiliary parts. |
| Technical Ceramics | Selected wear-resistant, insulating and corrosion-resistant parts. |
The suitability of engineering plastics and ceramics depends on operating temperature, pressure, medium compatibility and mechanical loading. Pressure-bearing, load-bearing and safety-critical components must be evaluated against the customer’s drawings and technical specifications.