Flanged Hollow Sleeve with through Hole for Bolted Flange Joints

Each Flanged Hollow Sleeve With Through Hole For Bolted Flange Joints from Qimao Metal Manufacturer is machined from solid bar stock or forged blanks, then heat-treated where specified. The through-hole diameter is sized 1–2mm larger than the nominal bolt diameter for easy assembly. Flange thickness ranges from 3mm to 15mm depending on load requirements.

Surface options include plain finish, zinc plating, or PTFE coating for chemical resistance. We stamp part numbers and material grades on the flange face for traceability. Dimensional tolerances follow ISO 2768-m or tighter upon request.

All edges are deburred. No sharp corners. The sleeve can be supplied with or without chamfered bore ends. We also offer non-standard bore offsets for retrofitting old flange patterns. Every batch includes a dimensional report. Hardness testing is available for high-strength grades.

Product Parameter (Specification)

Product Feature

• One-piece flanged design –The Flanged Hollow Sleeve With Through Hole For Bolted Flange Joints no loose washers or stacked shims. Faster assembly, fewer parts to lose.

• Precision through-hole – Bolt slides in easily but stays centered. No rattling under vibration.

• Real material options – Carbon steel (1045, A36), stainless (304, 316), or alloy (4140, 17-4PH). We stock common sizes.

• Flat flange face – Ground to within 0.1mm. Prevents bolt bending and uneven clamping.

• Deburred edges – Safe to handle with bare hands or gloves. No sharp corners.

• Custom lengths – Any length from 10mm to 200mm. No extra charge for non-standard sizes.

• Surface finishes – Plain, zinc plated, or PTFE coated. 316 stainless for offshore or chemical use.

• Traceable – Material grade and batch number stamped on the flange face.

Application

1. Pipeline flanges with bolts that are too long

Our Flanged Hollow Sleeve With Through Hole For Bolted Flange Joints instead of cutting bolts or stacking washers, use a sleeve to take up extra space. Nut tightens against a solid surface.

2. Valve actuator mounting

Acts as a standoff spacer between valve flange and actuator bracket. Through-hole keeps bolt centered.

3. Structural steel with slotted holes

Fills the slot width. Prevents bolt head from shifting. Flange covers slot edges for even load transfer.

4. Retrofitting old, misaligned flanges

Sleeve gives you room to adjust bolt angle. No hammering required.

5. Temporary flange spreading for gasket replacement

Protects flange holes from jacking bolt damage. Remove sleeve after job, install regular bolts.

6. Offshore pipe supports under vibration

Flanged end resists rotation. Through-hole keeps bolt centered even with side movement. 316 stainless lasts years.

7. Pump baseplate jacking bolts

Weld sleeve to baseplate. Guides jacking bolt and provides flat push surface. No loose blocks to lose.

8. PTFE-lined chemical pipes

Acts as a torque limiter. Prevents crushing the liner. Tighten until sleeve contacts flange faces.

9. Construction alignment of heavy flanges

Use sleeve as a lever to pull misaligned flanges together. Replace with standard bolt after alignment.

10. Hydraulic cylinder mounting brackets

Fills variable gaps between cylinder flange and bracket. Looks cleaner than stacked washers. Won't loosen over time.

Factory Advantage

We keep common steel and stainless blanks in stock for Flanged Hollow Sleeve With Through Hole For Bolted Flange Joints. Every sleeve is individually inspected for bore concentricity and flange parallelism. We do not use third-party subcontractors for machining — everything is done in-house.

Our quality team provides real-time photos during production if requested. We also offer sample machining before bulk orders. Many customers come back because we catch drawing errors before cutting metal, not after.