RAYCHIN LIMITED

Low-Profile Design

The domed button head provides a smooth, streamlined appearance with no sharp edges. The low-profile head reduces clearance requirements and prevents snagging on moving parts. Ideal for applications where space is limited or where a clean, aesthetic finish is required.

Reduced Turbulence

The smooth, rounded head profile minimizes fluid turbulence in flow applications, making these screws ideal for piping systems, pumps, and fluid handling equipment where flow efficiency is critical.

Precision Hex Socket Drive

Deep, accurate hex sockets allow for maximum key engagement and torque transfer without cam-out. Available with standard hex or Torx drive options for enhanced torque capability. Sizes from 1.5mm to 10mm (metric) and 1/16" to 3/8" (inch).

Cleanability

The smooth, recess-free head design prevents accumulation of debris, making these screws ideal for pharmaceutical, food processing, and clean room applications where hygiene is critical.

Incoloy 800 (UNS N08800 / 1.4876)

High-Temperature General Purpose: Nickel-iron-chromium alloy with excellent oxidation and carburization resistance up to 815°C. Good creep strength and resistance to sigma phase embrittlement. Ideal for heat exchangers, furnace components, and petrochemical applications. Minimum tensile strength: 585 MPa, yield strength: 240 MPa.

Incoloy 800H (UNS N08810 / 1.4958)

Enhanced High-Temperature Strength: Higher carbon content (0.05-0.10%) provides improved creep and rupture strength. Excellent performance up to 1150°C. Preferred for applications requiring long-term high-temperature stability such as ethylene furnace tubes and steam generators. Maintains structural integrity at extreme temperatures.

Incoloy 800HT (UNS N08811 / 1.4959)

Optimized High-Temperature Performance: Controlled chemistry with aluminum and titanium additions for enhanced creep resistance. Maximum service temperature up to 1150°C. Superior performance in cyclic temperature applications. Ideal for industrial furnace components, radiant tubes, and high-temperature structural fasteners.

Incoloy 825 (UNS N08825 / 2.4858)

Acid & Chloride Resistance: Nickel-iron-chromium alloy with molybdenum (2.5-3.5%) and copper (1.5-3%) additions. Exceptional resistance to sulfuric and phosphoric acids. Resists 40% H₂SO₄ at 100°C with <0.05mm/year corrosion rate. Ideal for chemical processing, acid storage, and marine applications. Maximum service temperature: 540°C in acid service.

Incoloy 925 (UNS N09925)

Sour Service Specialist: Precipitation-hardenable alloy with titanium additions (1.9-2.4%) providing significantly higher strength through aging. Excellent resistance to sulfide stress cracking in H₂S environments. Yield strength 760-965 MPa in aged condition. Ideal for oil & gas downhole tools, sour gas well equipment, and high-strength corrosion-resistant fasteners. Qualified per NACE MR0175.

Dimensional Standards

Our Incoloy button head cap screws meet or exceed the following specifications:

Available in UNC, UNF, UNJF-3A, and metric coarse/fine thread configurations.

Material Specifications by Grade

• Incoloy 800: ASTM B408 / ASME SB408, ASTM B163, ASTM B407
• Incoloy 800H: ASTM B408 / ASME SB408, ASTM B163, ASTM B407
• Incoloy 800HT: ASTM B408 / ASME SB408, ASTM B163, ASTM B407
• Incoloy 825: ASTM B424 / ASME SB424, ASTM B423, NACE MR0175
• Incoloy 925: ASTM B805, API 6A, NACE MR0175

Surface Finish Options

• Passivated: Per ASTM A967 for maximum corrosion resistance
• Electropolished: For clean room and pharmaceutical applications
• PTFE Coated: For anti-galling and lubricity
• Silver Plating: Per AMS 2410 for high-temperature anti-seize

Exceptional High-Temperature Strength (800 Series)

Incoloy 800H and 800HT maintain useful strength up to 1150°C. At 900°C, tensile strength remains 130-180 MPa, significantly higher than 316H. Excellent creep rupture strength at 1000°C with 20-25 MPa for 1000 hours.

Superior Acid Resistance (825)

Incoloy 825 button head screws resist 40% H₂SO₄ at 100°C with <0.05mm/year corrosion rate. Excellent performance in phosphoric acid service, including wet process phosphoric acid containing fluoride impurities.

Sour Service Excellence (925)

Incoloy 925 button head screws offer yield strength up to 760 MPa in aged condition with exceptional resistance to sulfide stress cracking. Qualified per NACE MR0175 for H₂S environments up to 425°C.

Low-Profile Design

The domed button head provides a smooth, streamlined appearance with no sharp edges. Ideal for applications where clearance is limited, or where a clean, aesthetic finish is required. Prevents material buildup and facilitates easy cleaning.

Chloride SCC Immunity

With high nickel content (30-46%), Incoloy button head screws have excellent resistance to chloride stress corrosion cracking, making them ideal for marine environments and brackish water applications.

Precision Hex Socket Drive

Deep, accurate hex sockets allow for maximum key engagement and torque transfer without cam-out. Available with standard hex and Torx drive options for enhanced torque capability.