Custom stainless hydraulic fittings made from samples and drawings

Some connections are not in any catalog: a discontinued adapter for an old machine, a transition part that joins two different thread standards, a flange block that has to fit into a tight installation space, or a spare for equipment sourced from abroad. In these cases, manufacturing starts from a sample or a technical drawing. Once port size, connection orientation and installation clearance are defined on the same drawing, production becomes predictable.

Which parts are manufactured?

• Conversion adapters between different thread standards, for example BSP to JIC/UNF or NPT to metric
• Nipples, elbows and tees in non-standard lengths, diameters or angles
• Flange blocks and SAE flange transitions matched to machine ports
• Remanufacture from samples of equipment parts that are no longer available
• Machined stainless steel parts used in steering, crane and actuation assemblies

From a sample or from a technical drawing?

If there is a technical drawing

A dimensioned drawing that specifies material grade, thread standard, tolerances and surface finish requirements is the fastest route. The drawing is reviewed for manufacturability; if any detail would complicate machining or inspection, it is flagged back to you with a suggestion before production.

If there is only a sample

The sample is measured, its thread standard is identified with a thread pitch gauge and diameter measurement, the sealing surface is examined and the dimensions are transferred to a drawing. With a worn or damaged sample, dimensions are evaluated together with the mating part and the operating conditions; worn dimensions are not copied as they are.

If there are photos and measurements

Outside diameter and thread pitch measured with a caliper, together with clear photos of the part from different angles, are enough for a preliminary assessment. For exact dimensions, the sample or the dimensions of the mating part are usually requested.

Process: input, approval, manufacturing

1. Input: the sample, dimensioned drawing, material requirement, quantity and operating conditions (pressure, temperature, fluid, environment) are collected.
2. Technical review: manufacturability, raw material diameter and machining sequence are checked.
3. Written confirmation: thread standard, sealing type and critical dimensions are mutually confirmed in writing before production.
4. First article: the first part is machined and passes dimensional inspection; it is submitted for approval if required.
5. Series production and final inspection: production runs to the approved dimensions, and each batch passes a final dimensional inspection.

Material selection

The preferred material for custom parts is AISI 316/316L, which provides corrosion resistance in saltwater, humid and chemical environments. If the part will be connected to a welded line, low-carbon 316L is preferred. If a different material is required, it should be specified on the technical drawing or in the request; raw material diameter and availability are factored into the lead time planning at this stage.

Why written confirmation?

The most expensive mistake on a custom part is a misunderstood dimension. "1/2 inch" could mean BSP or NPT. At this size, the two threads have the same pitch (14 threads per inch) and very similar diameters, but the thread angle (55° vs. 60°) and the sealing method are different. Having the thread standard, sealing type and critical dimensions in writing before production ensures both sides are talking about the same part, and makes it easier to produce the identical part on a repeat order.

Quality control

• Inspection of all critical dimensions on the first article
• Fit of the thread, cone and seal face to the mating part
• Burr, surface and deformation check
• Pressure and leak-tightness verification depending on the application
• Batch-by-batch final dimensional inspection and packaging with protective caps

Applications by sector

Parts subject to technical drawing approval in the defense industry; adapters for ground support and test equipment in aviation; spares for foreign-made equipment in marine and shipyards; transitions for mixed-standard lines on offshore facilities; port transitions for older machines in rolling mills and paper and board mills; process line-specific connections in chemical plants.

Lead time

Custom-size and project manufacturing is scheduled within an average of 10-20 business days after technical approval. The clock starts on the day technical approval is given; the sooner the dimensions, material and quantity are finalized, the sooner production starts. If standard fittings or hose assemblies are also needed alongside the custom part, everything can be planned for the same shipment.