Honed tubes: defining bore and cylinder requirements

A honed tube has an inner bore finished by honing; seamless and welded construction must be specified separately. It forms the barrel of a hydraulic cylinder, where bore diameter, roundness and surface finish influence the movement of the piston and seals.

Start with the finished bore, not just the outside diameter.

The finished honed/SRB tube reference lists E355+SR, H8 bore tolerance, straightness ≤0.8 mm/m and eccentricity ≤4%. The published roughness is ≤0.2 μm without a named Ra/Rt parameter. Its dimension notation does not explicitly label OD and ID; confirm the actual pair, length and measurement criteria. H9 cold-drawn tubes are a separate supply condition. None of these values establishes a pressure rating.

Honing finishes the bore using an abrasive process. SRB uses skiving followed by roller burnishing and is often considered for batch cylinder production. Honing remains an option for varied sizes, repair and custom requirements. Select the process with the bore geometry and sealing requirements, rather than choosing by the lowest Ra value alone.

Material options in the knowledge base include ST52/E355, SAE1026, CK45, 20MnV6 and 42CrMo4. Specify the exact designation, delivery condition and applicable standard. Pressure capability depends on the actual material, wall thickness and cylinder design; the tube name alone does not determine it.

A ready-to-hone tube is a semi-finished blank with allowance for final bore processing. State the machining allowance, ID, OD, wall thickness, length and any heat-treatment or end requirements. It should not be ordered as if it were an already finished honed bore.

Confirm ID and roundness inspection, roughness, straightness, material records and any additional tests required by the drawing. MYLER normally wraps honed tubes in paper before packing them in wooden cases, helping protect against scratches and knocks during handling and transport. Specify any additional bore-protection requirements with the inquiry. Request MTC or EN 10204 3.1 documents with the inquiry and agree their scope.

Send the material, ID × OD or wall thickness, finished length, bore tolerance, roughness, quantity, drawing and destination to info@chromerods.com. Confirm whether you require honed, SRB or ready-to-hone material so the quotation describes the correct supply condition.