Product Overview
Round Threaded Inserts provide reliable, high-strength internal threads for circular hollow structural sections (HSS), commercial piping, and round metal tubing. Engineered as a fast, weld-free assembly solution, these press-fit components enable the direct, concentric mounting of leveling feet, heavy-duty casters, and adjustable glides while sealing raw tube ends against moisture, dust, and internal oxidation.
Technical Performance & Material Specifications
|
Parameter |
Grade A: Commercial Polypropylene |
Grade B: Industrial Nylon (PA6) |
Grade C: Premium Marine Nylon (PA66) |
|
Housing Material |
Virgin Polypropylene (PP) |
Polyamide 6 (PA6) + Impact Modifier |
Polyamide 66 + 30% Glass Fiber (PA66-GF30) |
|
Nut Insert Material |
Blue-White Zinc-Plated Steel |
Trivalent Zinc-Plated Carbon Steel (Grade 4.8) |
Austenitic Stainless Steel (SUS304 / SUS316) |
|
Axial Pull-Out Force |
2.8 kN or higher |
5.5 kN or higher |
7.8 kN or higher |
|
Max Stripping Torque |
22 Nm |
38 Nm |
52 Nm |
|
Hardness Shore D |
70D |
82D |
88D |
|
Operating Temp Range |
-10 to 60 degrees Celsius |
-30 to 95 degrees Celsius |
-40 to 140 degrees Celsius |
|
UV Resistance Rating |
Standard Indoor |
Accelerated Weathering (300 hrs) |
Carbon Black UV Stabilized (1000 hrs or higher) |
Advanced Product Features & Engineering Data
360-Degree Radial Interference: Features continuous circumferential fins with an engineered 0.15mm taper. Progressive radial compression compensates for tube ovality up to ±0.3mm, ensuring a uniform, centered fit.
Monolithic Structural Anchoring: Metal nuts are permanently encapsulated via insert-molding (240°C to 280°C window). 0.8mm pitch diamond knurling and a hexagonal profile lock the nut into the matrix, preventing spinning under pneumatic drivers.
Flush Edge Sealing: A 90-degree clean shoulder flange with a radius transition aligns flush against deburred tube profiles. Blocks ambient moisture and washdown fluids to prevent internal pipe oxidation.
On-Site Manufacturing Quality Control
Pneumatic Torque Testing
Random batch testing on digital torque benches to destructive failure to ensure rotational stress limits exceed standard manual assembly ratings.
100% Go/No-Go Calibration
Mechanized inline optical sorting and physical plug gauge calibration guarantee burr-free thread travel with zero pitch deviation.
Melt Flow Index (MFI) Uniformity
Inbound resin testing verifies molecular weight consistency to prevent micro-voids, brittle flanges, or weak knit lines.
Customization & Engineering Capabilities
|
Customization Type |
Engineering Options |
Production Minimum (MOQ) |
Lead Time & Support |
|
Thread Profiles |
• Non-standard metric sizes • Fine pitches • Fractional Imperial threads (1/4"-20, 5/16"-18, 3/8"-16, 1/2"-13 UNC/UNF) |
2,500 units (Utilizes modular mold inserts to avoid full tooling costs) |
Physical samples within 7 working days |
|
Dimensions & Profiles |
• Heavy-walled pipe profiles • Non-standard gauge tubing diameters • Custom aluminum extrusion fittings |
10,000 units (Requires custom mold development for new outer geometries) |
• 3D CAD modeling within 48 hours • Finite Element Analysis (FEA) within 48 hours |
|
Material & Color |
• Custom color matching (RAL / Pantone via spectrophotometer) • Flame-retardant compounding (UL94-V0 compliance) • Glass-fiber reinforcement ratios (15% to 50%) |
Contact sales for batch minimums |
Color plaque validation before full production run |
Why Choose Bai Ye Industrial
50-Year History
Founded in 1975, we have 50 years of expertise in steel pressed tube metal adapters and custom plastic injection molding.
Automated Capacity
Our upgraded Hua-tan facility (since 2015) utilizes advanced automatic machines to ensure high capacity and strict dimensional control.
25 Years Exporting
Since 2001, our international trade department has provided 25 years of reliable global logistics and OEM/ODM services.
SGS Certified
An ISO 9001:2015 certified factory with products fully passing SGS testing for RoHS, California Prop 65, and BIFMA standards.
How to install it?
Global Logistics, Packaging & Shipping Compliance
We maintain standardized industrial packaging and export logistics frameworks to ensure seamless warehouse integration upon arrival:
Export Packing Standards: Standard shipments are packed in heavy-duty, double-wall corrugated shipping boxes (25 kg maximum per box) stacked on standard 1200mm x 800mm heat-treated fumigated pallets, completely wrapped in multi-layer UV-blocking stretch film.
Moisture-Proof Protection: All individual parts are pre-sealed in heavy-duty PE bags (0.08mm thickness) with integrated desiccant packs to protect carbon steel threads from salt-air oxidation during long-distance ocean freight.
Automated Warehouse Labeling: Every carton includes customized, high-contrast labels containing your internal part numbers, purchase order (PO) numbers, batch data, QR codes, and EAN-13/UPC-A barcodes for instantaneous warehouse scanning.
International Shipping Terms: We provide flexible trade terms including FOB (Major domestic ports), CIF (Destination port), and turnkey DDP options (including customs clearance and local delivery directly to your distribution center).
FAQ
Q: What specific raw tube tolerances can your round inserts accommodate without slipping?
Our multi-rib design is engineered with flexible, deformable outer fins that adapt to an internal tube diameter variation of up to plus/minus 0.4mm. For example, a standard insert designed for a 38mm outside diameter tube with a 1.5mm wall thickness will reliably grip tubes with internal diameters ranging from 34.6mm to 35.4mm while maintaining its structural pull-out resistance.
Q: Can we receive free physical samples for laboratory load and fitment testing before placing a commercial order?
Yes. We maintain a comprehensive sample inventory of all standard metric thread configurations (M6 through M12) across our standard outside diameters. We provide up to 10 complimentary sample units per size for engineering evaluations. Freight charges can be applied directly to your corporate DHL, FedEx, or UPS account.
Q: How do your inserts handle dynamic rolling loads when used with heavy-duty industrial casters?
For applications involving continuous rolling movement, directional shifts, or high side leverage, we mandate our Grade C (PA66-GF30 with Stainless Steel Thread) series. The 30% glass-fiber reinforcement gives the polymer matrix high structural modulus and tensile strength, preventing the round tube end from expanding, flaring, or becoming ovalized under heavy, repeating dynamic side loads.
Q: How do you verify that the plastic flanges will not fracture when driven into steel tubes by manual rubber mallets or automated assembly lines?
We use virgin, high-molecular-weight polymers blended with specific elastomeric impact modifiers rather than brittle, degraded post-consumer recycled plastics. Structurally, the internal transition junction between the vertical rib body and the horizontal top flange is reinforced with thick radius gussets that dissipate downward impact energy away from the visible face cap.
Q: What is the standard production lead time for a custom color run or a non-catalog thread size?
For modular tool adjustments (such as changing an M8 core to a 5/16"-18 thread using standard black nylon), production takes 10 to 14 business days from formal drawing approval. For completely custom colors requiring a specific Pantone formulation or full custom-molded geometries, the lead time is 21 to 28 days, which includes color plaque approval, masterbatch compounding, and high-volume inline production.
Q: Can these round inserts withstand automated conveyor chemical washdowns in food processing or medical cleanroom environments?
Yes. For sanitary, medical, or food-processing applications, we offer a specialized formulation pairing pure Polypropylene (PP) or virgin Polyamide 66 (PA66) with a Grade 316 stainless steel nut insert. This assembly guarantees complete resistance to corrosive cleanroom sanitizers, industrial detergents, alcohol washdowns, and high-humidity environments without experiencing hydrogen embrittlement or surface rust lockups.
Hot Tags: round threaded inserts, round threaded inserts manufacturers, suppliers, factory, Caster Sockets for Round Tubing, plastic insert, Round Threaded Inserts, Square Caster Socket, Square Tube End Plugs, Square Tube Nut Insert
