Carbon Steel Bushing — Factory Direct Supplier | Huaxia-Steel
Carbon steel bushings are threaded pipe fittings used to connect pipes or fittings of different sizes, functioning as reducers in threaded piping systems. As a factory-direct manufacturer, Huaxia-Steel produces hex-head bushings and flush bushings to ASME B16.11, MSS-SP-95, and BS 3799 standards, covering sizes from 1/4″ to 4″. Our bushings are forged from ASTM A105 carbon steel with pressure ratings up to 6000 psi, serving oil & gas, chemical processing, and industrial piping applications. Full EN 10204 3.1 certification and heat number traceability ensure compliance with international piping codes.
Product Overview
A bushing is a threaded fitting with male threads on the outside and female threads on the inside, designed to reduce a threaded connection from one pipe size to a smaller size. The male thread screws into a larger fitting, while the female thread accepts a smaller pipe or fitting. Hex-head bushings feature a hexagonal section for wrench tightening, while flush bushings (also called straight bushings) have no hex head and are tightened using a socket wrench or internal tool.
Huaxia-Steel manufactures bushings using a hot-forging process from carbon steel bar stock, followed by precision machining of both internal and external threads. The forging process ensures a dense, defect-free structure, while CNC machining guarantees accurate thread geometry for pressure-tight connections. External threads are machined to ASME B1.20.1 NPT taper specifications, and internal threads are reamed and tapped to matching standards.
Specifications & Dimensions
Hex-Head Bushings — ASME B16.11, Class 6000
| Reduction (in) | Hex Size (mm) | Overall Length (mm) | Male Thread Length (mm) | Female Thread Depth (mm) |
|---|---|---|---|---|
| 1/2 × 1/4 | 30 | 35 | 15 | 14 |
| 1/2 × 3/8 | 30 | 35 | 15 | 14 |
| 3/4 × 1/2 | 38 | 38 | 17 | 15 |
| 1 × 1/2 | 46 | 44 | 19 | 17 |
| 1 × 3/4 | 46 | 44 | 19 | 17 |
| 1-1/4 × 1/2 | 56 | 48 | 21 | 17 |
| 1-1/4 × 3/4 | 56 | 48 | 21 | 17 |
| 1-1/4 × 1 | 56 | 48 | 21 | 19 |
| 1-1/2 × 1/2 | 62 | 51 | 22 | 17 |
| 1-1/2 × 3/4 | 62 | 51 | 22 | 17 |
| 1-1/2 × 1 | 62 | 51 | 22 | 19 |
| 1-1/2 × 1-1/4 | 62 | 51 | 22 | 21 |
| 2 × 1 | 75 | 57 | 25 | 19 |
| 2 × 1-1/4 | 75 | 57 | 25 | 21 |
| 2 × 1-1/2 | 75 | 57 | 25 | 22 |
| 2-1/2 × 2 | 92 | 64 | 28 | 25 |
| 3 × 2 | 108 | 70 | 30 | 25 |
| 4 × 2 | 140 | 83 | 34 | 25 |
| 4 × 3 | 140 | 83 | 34 | 30 |
Flush Bushings — MSS-SP-95
| Reduction (in) | Overall Length (mm) | Body Dia (mm) | Approx Weight (kg) |
|---|---|---|---|
| 1/2 × 1/4 | 25 | 27 | 0.06 |
| 3/4 × 1/2 | 29 | 33 | 0.09 |
| 1 × 1/2 | 32 | 42 | 0.15 |
| 1 × 3/4 | 32 | 42 | 0.14 |
| 1-1/4 × 1 | 38 | 52 | 0.25 |
| 1-1/2 × 1 | 41 | 58 | 0.33 |
| 2 × 1 | 44 | 70 | 0.50 |
| 2 × 1-1/2 | 44 | 70 | 0.48 |
| 3 × 2 | 54 | 96 | 1.10 |
| 4 × 3 | 64 | 130 | 2.20 |
Available Grades & Materials
| Grade | Standard | Carbon (%) | Yield (MPa) | Tensile (MPa) | Hardness (HB) |
|---|---|---|---|---|---|
| A105 | ASTM A105 | ≤0.35 | 205 | 485 | 137–187 |
| A350 LF2 | ASTM A350 | ≤0.30 | 250 | 485 | 140–197 |
| ST37.0 | DIN 1629 | ≤0.17 | 235 | 360–510 | ≤170 |
| 20# | GB/T 699 | 0.17–0.24 | 245 | 410 | ≤156 |
| 16Mn | GB/T 1591 | 0.13–0.19 | 345 | 510 | ≤197 |
Manufacturing Standards
- ASME B16.11: Forged Steel Fittings, Socket-Welding and Threaded
- MSS-SP-95: Swaged Nipples and Bull Plugs (covers flush bushings)
- BS 3799: Steel Pipe Fittings, Screwed and Socket-Welded
- DIN 2982: Threaded Pipe Plugs and Bushings
- GB/T 14383: Forged Steel Socket-Welding and Threaded Fittings
Applications
- Oil and gas piping size reductions
- Refinery process piping transitions
- Chemical plant piping systems
- Instrumentation connections (reducing from main line to instrument tubing)
- Water and gas distribution networks
- Steam and condensate piping
- Pressure vessel connections
- Maintenance and repair of existing threaded piping systems
Quality Assurance
Every production batch of bushings undergoes the following quality control procedures:
Packaging & Shipping
- Standard packaging: wooden cases with polyethylene inner lining
- Small sizes (1/4″–1″): bulk in bags, 200–1000 pcs per wooden case
- Medium sizes (1-1/4″–2″): individually wrapped, 100–300 pcs per case
- Large sizes (2-1/2″–4″): individually packed, 50–100 pcs per pallet
- Marking: reduction size, grade, class, standard, heat number, country of origin
- ISPM-15 heat-treated pallets for international shipping compliance
- VCI anti-corrosion paper and desiccant for sea freight
- Loading photos and detailed packing list provided with every shipment
Why Choose Huaxia-Steel for Bushings?
- Factory-direct pricing: No intermediary markup — save 15–25% compared to trading companies
- Complete size range: All standard reductions from 1/4″ to 4″ in stock or short lead time
- Full traceability: Heat number marking on every piece, traceable through MTC
- Threaded expertise: Precision NPT threading verified by gauges for pressure-tight seals
- Flexible MOQ: From 200 pieces for standard sizes; custom configurations from 500 pieces
- Global export experience: Shipping to 80+ countries with proper documentation
Conclusion
Carbon steel bushings are essential reducing fittings in threaded piping systems, providing reliable size transitions for pressure-containing applications. Huaxia-Steel’s factory-direct manufacturing ensures consistent quality, precise threading, and competitive pricing across our bushing range. From standard hex-head bushings to flush configurations, we deliver products that meet international standards and your specific project requirements. Contact us today for a quotation — our technical team will respond within 24 hours with detailed specifications and pricing.
