Single-passage threaded rotary joint for pneumatic and light fluid applications. Compact 0.08 kg aluminum body or 0.45 kg steel body. PTFE composite seal rated for 1 MPa and 500 RPM. Ships in 7 days from Ningbo. Used on handheld pneumatic tools, small rotary tables, and hose anti-twist connections where weight and simplicity matter.
BP-1P-0003 is a single-passage rotary joint designed for low-pressure pneumatic and light fluid transfer. The PTFE composite seal provides low friction torque (0.02–0.04 N·m) and chemical resistance across air, water, and coolant media. The 45# steel body offers high rigidity for stationary mounting; the optional aluminum body reduces weight by 82% for handheld tool applications.
| Model Number | BP-1P-0003 |
|---|---|
| Number of Passages | 1-in-1-out (single passage) |
| Mount Type | Threaded (BSP parallel, G1/4 or G1/8) |
| Max Pressure | 1 MPa (10 bar / 145 psi) — derate to 0.7 MPa for continuous water duty |
| Max Speed | 500 RPM — derate to 300 RPM for continuous water or coolant |
| Body Material | 45# steel (standard) / 6061-T6 aluminum (lightweight option) |
| Seal Type | PTFE composite seal with FKM O-ring backup |
| Compatible Media | Air, water, coolant, light hydraulic oil (ISO VG 32 max) |
| Operating Temperature | -20°C to +120°C |
| Net Weight | Approx. 0.08 kg (aluminum) / 0.45 kg (steel) |
| Friction Torque | 0.02–0.04 N·m (air) / 0.03–0.05 N·m (water) |
| Certifications | ISO 9001:2015, CE, RoHS |
| Warranty | 12 Months |
45# steel body: Chinese standard carbon steel (equivalent to AISI 1045). Yield strength 355 MPa, hardness 170–210 HB. Suitable for stationary mounting where rigidity and thread strength matter. Not recommended for continuous water exposure without surface treatment — specify nickel plating or stainless steel (304/316) for wet environments.
PTFE composite seal: Polytetrafluoroethylene with glass fiber and graphite filler. Self-lubricating, chemically inert, and rated for -200°C to +260°C. The composite structure provides structural integrity while maintaining the low friction coefficient (0.05–0.10 against steel) that makes PTFE ideal for rotary seals. FKM O-ring provides static sealing at the housing interface.
When to choose aluminum: For handheld tools, robot EOAT, or any application where the joint moves with the operator. The 0.08 kg aluminum body adds negligible load compared to the 0.45 kg steel version. Aluminum is not recommended for abrasive coolant or high-impact environments.
BP-1P-0003 is designed for single-air-line applications where weight, simplicity, and cost matter more than multi-channel complexity. This model may be suitable for the listed applications when its passage count, mounting, medium, pressure, speed, and temperature limits match the machine requirements.
Proper installation extends seal life from 6 months to 12+ months. The most common cause of early failure is overtightening the threaded connection, which distorts the seal housing and creates a leak path. Follow these steps for reliable operation.
BP-1P-0003 uses BSP parallel (G) threads — G1/4 or G1/8. Confirm your equipment uses the same thread standard. Do not use NPT or metric adapters — they add 10–20 mm length and create a stress concentration that cracks under side load. If your tool has NPT1/4, order the NPT thread option or use a thread-matched swivel. Download the 2D drawing for exact dimensions, pitch, and tolerances.
Use PTFE tape (3–4 wraps) or anaerobic liquid thread sealant on the male threads. Hand-tighten plus 1/4 turn maximum. Overtightening distorts the seal housing, compressing the PTFE seal unevenly and creating a leak path within days. Torque spec: 8–12 N·m for G1/4, 5–8 N·m for G1/8. Use a torque wrench — "finger tight plus a quarter turn" is not precise enough for a 0.45 kg steel body.
BP-1P-0003 is a threaded-mount joint — it does not have a built-in anti-rotation tab. For stationary mounting (machine frame to rotating shaft), the stationary side must be locked against rotation. Use a bracket, clamp, or set screw to prevent the body from spinning with the shaft. Never let the body rotate freely — the hose will twist and the seal will experience reverse torque, accelerating wear.
Use flexible hoses (not rigid pipe) to connect the stationary side to the air supply. Rigid pipe transfers vibration and thermal expansion directly to the joint, stressing the seal. Install a 40-micron filter upstream to protect the PTFE seal from debris. For water or coolant, add a Y-strainer (60 mesh) to prevent particulate damage.
Run at low pressure (0.2 MPa) and low speed (50–100 RPM) for 5 minutes without load. This beds the PTFE seal against the shaft surface, creating a micro-smooth contact zone. Check for leaks at the thread and seal interfaces. If dry, gradually increase to operating pressure and speed over 10 minutes. Skipping the run-in is the #2 cause of early seal failure — the seal needs time to conform to the shaft surface finish.
Full dimensions, tolerances, thread specs (G1/4 and G1/8), shaft finish requirements, and seal groove details. 120 KB.
Free 3D files provided after inquiry. Includes aluminum and steel body variants, G1/4 and G1/8 thread options. Use for CAD fit verification before ordering.
Complete guide: thread matching, torque specs, anti-rotation, filtration, run-in procedure, and maintenance checklist. 650 KB.
45# steel material traceability, hardness test report, and RoHS compliance certificate. Available upon request with order.
Not sure if BP-1P-0003 is the right model? Use this comparison to decide — and know exactly when to upgrade to a multi-passage or higher-pressure joint.
| Your Requirement | BP-1P-0003 Fit | Better Alternative | Why Upgrade |
|---|---|---|---|
| Single air line, handheld tool, weight critical | ✅ Perfect — 0.08 kg aluminum | — | — |
| Single air line, stationary machine, rigidity critical | ✅ Good — 0.45 kg steel | — | — |
| Clamp + unclamp (2 independent lines) | ❌ Too few passages | BP-2P-0001 | 2 passages with independent seals, flange mount for rigidity |
| Pressure >1.0 MPa (e.g., 1.2 MPa hydraulic) | ❌ Over pressure rating | BP-2P-0002 | 1.5 MPa rated, same threaded mount, dual passage |
| Dusty or abrasive environment (steel mill, foundry) | ❌ No dust protection | BP-2P-50-0001 | Dust-proof seal and protective shroud |
| Food-grade or medical cleanroom | ❌ Standard FKM not FDA | Custom FDA-grade | FDA 21 CFR 177.2600 compliant FKM or EPDM seal |
| Continuous water immersion | ⚠️ Risk of rust | Stainless steel version | 304 or 316 stainless body with passivation |
The #1 cause of BP-1P-0003 warranty claims is overtightening. A technician uses a pipe wrench and applies 25 N·m on a G1/4 thread rated for 8–12 N·m. The housing distorts, compressing the PTFE seal unevenly. Incorrect installation or operation outside the specified limits can cause premature leakage. Failure timing depends on alignment, medium, pressure, speed, temperature, and duty cycle. The technician blames the seal quality and requests a replacement — but the root cause was installation torque. Rule: Use a torque wrench. Hand-tighten plus 1/4 turn maximum. For G1/4: 8–12 N·m. For G1/8: 5–8 N·m.
A machine builder needs clamp and unclamp air for a rotary table. To save $15, they buy BP-1P-0003 and T-fitting the single passage into two lines. The result: when the clamp line pressurizes at 0.6 MPa, the T-fitting leaks 0.15 MPa into the unclamp line — the fixture releases prematurely, dropping the workpiece. Rule: BP-1P-0003 is single-passage only. For 2+ independent functions, use BP-2P-0001 or BP-2P-0002. The $15 savings cost $200 in scrapped parts.
A maintenance team installs BP-1P-0003 on a labeling machine and immediately runs it at 0.8 MPa and 300 RPM. The PTFE seal has not bedded into the shaft surface — microscopic high spots create leak paths. Within 2 weeks, vacuum drops from -0.07 MPa to -0.04 MPa, and labels fall off. The team replaces the seal, but the same thing happens again because they skip the run-in every time. Rule: Run at 0.2 MPa and 50–100 RPM for 5 minutes before full operation. This beds the seal and extends life from 6 months to 12+ months.
Other rotary joints commonly purchased with BP-1P-0003 — or the models you upgrade to when your application outgrows a single passage.
The steel body (0.45 kg, 45# steel) provides higher rigidity and thread strength for stationary mounting on machine frames. The aluminum body (0.08 kg, 6061-T6) reduces weight by 82% for handheld tools and robot EOAT where every gram matters. Both use the same PTFE seal and have identical pressure and speed ratings. Steel is standard; aluminum is available on request with 3-day additional lead time.
Yes — the PTFE composite seal and FKM O-ring are compatible with water, water-soluble coolant, and light hydraulic oil (up to ISO VG 32). For continuous water duty, derate pressure to 0.7 MPa and speed to 300 RPM to reduce seal wear. The 45# steel body has good corrosion resistance for intermittent water exposure, but continuous immersion requires nickel plating or stainless steel (304/316) specification. If your application involves deionized water or aggressive coolant, contact Begapunk for seal compatibility review.
BP-1P-0003 uses BSP parallel (G) threads per ISO 228-1 — G1/4 (standard) or G1/8 (optional). BSP parallel threads seal on a gasket or O-ring at the port face, not on the thread itself. This means PTFE tape on the thread is for sealing only; the mechanical connection is made by the flat face compressing against the mating port. Download the 2D PDF drawing for exact thread dimensions, pitch (1.337 mm for G1/4, 0.907 mm for G1/8), and tolerances. NPT and metric thread options are available as custom orders.
Yes — free 3D STEP and IGES files are provided after you send an inquiry. The file includes both aluminum and steel body variants, G1/4 and G1/8 thread options, and the anti-rotation bracket mounting hole pattern. Use the 3D file to verify clearance, port direction, and thread engagement length in your CAD assembly before ordering. 3D files may be provided for qualified projects after the application requirements are reviewed. File availability and response time depend on the model and the project information provided.
Upgrade when your application needs 2 or more independent air functions. Common triggers: (1) You add a second gripper or vacuum cup to a single-air-line fixture — T-fitting a single passage causes pressure interference and leaks. (2) Your pressure requirement exceeds 1.0 MPa — BP-2P-0002 handles 1.5 MPa. (3) You move from a handheld tool to a stationary rotary table — BP-2P-0001's flange mount provides better rigidity than threaded mount. (4) Your environment becomes dusty or abrasive — BP-2P-50-0001 has dust-proof protection. The upgrade cost is typically $15–$40 more than BP-1P-0003, but it prevents the $200+ cost of scrapped parts from pressure interference.
We design custom rotary joints for any number of passages, pressure, thread type, and mounting style. Free 3D STEP file with every inquiry. Typical custom lead time: 10–14 days.
Request Custom Design →Technical Note: All pressure ratings, speed ratings, and material specifications referenced on this page are based on Begapunk BP-series standard pneumatic rotary joints tested under controlled laboratory conditions. Actual performance depends on operating conditions, media quality, installation practices, and maintenance schedule. For applications outside standard ratings — including high-pressure hydraulic, continuous water immersion, food-grade, or cleanroom environments — consult Begapunk factory engineering before specification. Last updated: June 11, 2026.