Custom Machining of Threaded Fittings Per Drawing
We manufacture custom CNC machined threaded fittings strictly according to customer drawings, samples and technical specifications. As a custom threaded fittings manufacturer, we machine every element of a fitting to order — material, overall dimensions, thread form and tooth profile, taper, crest and root geometry, pitch and lead, tolerance class and surface treatment. Send a drawing, a sketch, a worn sample or a reverse-engineered part, and we produce the matching CNC machined threaded fitting.
Our capability covers both standard thread series and fully non-standard, special and modified threads: internal and external threads, straight and tapered threads, single-start and multi-start threads, right-hand and left-hand threads, from tiny instrument fittings to heavy-walled hydraulic and pipeline adapters. Production runs from a single machined prototype through small batches to large-volume, repeatable serial orders.
Per Drawing or Sample
Drawings, STEP / IGES files, sketches or physical samples — including reverse engineering of legacy and obsolete threaded fittings.
Any Material, Any Size
Stainless and carbon steels, brass, bronze, aluminum, titanium, super alloys and engineering plastics, in inch and metric dimensions.
Standard + Non-Standard Threads
NPT, NPTF, BSPP, BSPT, metric, UN/UNF and SAE profiles, plus fully custom, special and modified non-standard thread forms.
One Piece to Mass Production
CNC machined prototypes, pilot batches and high-volume production with consistent repeatability from first article to last piece.
CNC Machined Threaded Fittings We Manufacture
A selection of custom machined threaded fittings produced per customer drawing: thread couplings, quick connectors, hydraulic pipe fittings and multi-way fittings in stainless steel and other customer-specified materials.
Every Parameter of the Threaded Fitting Is Customizable
When we machine threaded fittings per drawing, nothing is forced into a catalogue size. The eight parameter groups below are defined by your drawing and application, and each can be adjusted independently to solve sealing, assembly, pressure or interchangeability problems.
Material Selection
CNC machined threaded fittings in stainless steel 304/304L, 316/316L, carbon and alloy steel, brass, bronze, copper, aluminum 6061/7075, titanium, duplex and super-duplex steel, Inconel, Hastelloy, Monel and machinable engineering plastics such as PEEK, PVDF, Delrin and nylon — chosen for corrosion resistance, pressure rating, temperature range or weight.
Dimensions and Geometry
Outer and inner diameters, overall length, hex and wrench flats, shoulder and step geometry, bore size, chamfers and undercuts are all machined to drawing. Straight fittings, reducing adapters, elbows, tees, crosses, bushings, nipples, plugs, caps, standoffs, sleeves, extended-length and long-reach threaded fittings are produced as one-off or repeat designs.
Thread Form and Tooth Shape
The complete thread profile is machined to specification — V-type 60-degree and Whitworth 55-degree forms, rounded or truncated profiles, ACME and trapezoidal forms, buttress and special asymmetrical forms. Flank angles, pitch diameter and thread engagement length are controlled for smooth assembly and correct thread interference.
Taper Control
Tapered threads such as NPT, NPTF and BSPT are cut with closely controlled taper per foot / taper ratio so that sealing occurs at the correct wrenching engagement. Straight (parallel) threads such as BSPP, metric and SAE boss threads are machined with precise pitch diameter for O-ring, gasket or metal-face sealing.
Crest Geometry
The crest — the top surface of each thread tooth — is machined to the required flat width or radius. Crest truncation, crest radius and crest surface quality are controlled to avoid sharp edges, stress risers and galling, which is especially important for stainless steel threaded fittings and repeated make-and-break assembly.
Root Geometry
The root — the valley between adjacent teeth — is cut to the specified root radius or flat. A controlled, smooth root radius distributes assembly and pressure stress, reduces crack initiation under cyclic hydraulic loading, and is a defining feature of high-precision CNC machined threaded fittings used in high-pressure fluid systems.
Pitch, Lead and Starts
Coarse and fine pitches, constant and variable lead, single-start, double-start and multi-start threads, right-hand and left-hand threads are all machined to order. Custom lead and multi-start designs are used where fast assembly, axial adjustment or travel-per-rotation performance is required.
Surface Treatment and Finish
Passivation, electropolishing, mechanical and mirror polishing, zinc and nickel plating, black oxide, anodizing, hard anodizing, powder coating, tumbling and customized Ra surface roughness are available, along with dry-film lubricant and anti-galling coatings for stainless threaded fittings.
Standard Thread Series and Fully Custom Non-Standard Threads
We do not limit production to off-the-shelf thread standards. Our CNC turning and thread-cutting process follows an existing standard when one exists, and machines a completely custom thread profile when the application demands it.
Standard Threads Machined to Specification
We machine standard internal and external threads with controlled pitch diameter, thread depth and gauge engagement, using plug and ring gauges for verification.
- NPT / NPSC / NPSM — ANSI/ASME B1.20.1 tapered and straight pipe threads
- NPTF / PTF-SAE — dryseal threads designed for metal-to-metal sealing without sealant
- BSPP (G / Rp) — British standard parallel pipe threads for washer and O-ring sealing
- BSPT (R / Rc) — British standard tapered pipe threads
- ISO metric threads M, fine pitch MF — DIN / ISO standard machine threads
- UNC, UNF, UNEF, UN, UNS — unified inch threads, constant-pitch series included
- SAE straight thread O-ring boss (ORB / JIC) for hydraulic fittings
- ACME, trapezoidal (Tr), buttress and Whitworth profiles for power and legacy equipment
Completely Custom Non-Standard Threads
Beyond standard series, we design and machine non-standard threads that no catalogue fitting can offer. This is the core of our per-drawing custom threaded fittings service: the thread profile itself becomes an engineering variable.
- Modified pitch, modified flank angle and custom included angle (non-60° / non-55°)
- Custom taper rate and custom wrenching engagement length
- Special crest width / radius and special root radius defined on your drawing
- Multi-start and twin-start custom lead threads for fast coupling
- Hybrid threads combining a sealing section with a fastening section
- Stub threads, extra-fine threads and oversized / undersized repair threads
- Reverse-engineered threads from worn or imported samples, including obsolete equipment
- Mixed-end fittings: different thread types or sizes on each end, male/female combinations
Features and Applications of High-Precision Threaded Fittings
High-precision CNC machined threaded fittings are characterized by tight dimensional control, clean thread surfaces, accurate coaxiality and repeatable interchangeability. These qualities determine whether a fitting seals under pressure, assembles on the production line without rework, and survives years of vibration and thermal cycling.
Reliable Leak-Tight Sealing
Accurate taper, pitch diameter and surface finish let tapered threads seat at a repeatable position, while precisely machined sealing faces and O-ring grooves give straight-thread fittings controlled compression — essential for gas, liquid, vacuum and high-pressure hydraulic circuits.
Interchangeability and Consistency
Gauge-controlled threads and CNC repeatability mean every production lot assembles with matching torque against standard mating parts. First articles, repeat orders and spare parts remain interchangeable even months or years apart.
Pressure and Fatigue Resistance
Smooth root radii remove stress concentrations, while controlled wall thickness and material selection support high working pressure, pressure pulsation and vibration in hydraulic, pneumatic and process systems without premature cracking.
Clean, Burr-Free Fluid Paths
Deburred bores, smooth transitions and controlled internal surface roughness reduce turbulence, particle traps and dead volume — important for instrumentation, medical gas, food and beverage, semiconductor and analytical fluid systems.
Hydraulic Systems
CNC machined hydraulic threaded fittings, adapters and O-ring boss connectors for fluid power packs, cylinders, valves and high-pressure hose assemblies.
Pneumatic Systems
Precision threaded connectors, push-in fitting bodies and quick connectors for compressed-air circuits, automation manifolds and pneumatic cylinders.
Oil, Gas and Petrochemical
Stainless and alloy steel threaded couplings, nipples and reducer fittings for pipelines, metering skids, instrumentation taps and process piping.
Instrumentation and Analysis
Small-bore precision threaded fittings for gauges, sensors, transmitters, sampling lines and laboratory analytical equipment where dead volume must be minimal.
Automotive and Transportation
Custom threaded fittings for fuel lines, brake and cooling systems, turbo oil lines, sensor mounts and fluid transfer assemblies in vehicles and rail equipment.
Food, Beverage and Medical Gas
Electropolished stainless CNC machined threaded fittings with smooth, cleanable surfaces for beverage dispensers, dosing equipment and medical gas distribution.
Marine and Chemical Processing
Corrosion-resistant threaded fittings in 316L, duplex, Hastelloy and titanium for seawater, chemical dosing, water treatment and aggressive-media environments.
Semiconductor and Vacuum
Tight-tolerance threaded fittings and custom adapters for gas delivery panels, vacuum tooling and cleanroom fluid modules demanding particle-free surfaces.
Achievable Surface Quality and Dimensional Accuracy
Our CNC turned and CNC milled threaded fittings are produced under controlled machining conditions and verified with gauges, optical measuring and coordinate measuring equipment. The values below represent the precision levels that can be achieved on custom machined threaded fittings, applied according to drawing requirements and part geometry.
General Dimensional Tolerance
Turned diameters, lengths and bores can be held to tight linear tolerances, with tighter grades available on critical mating surfaces defined in the drawing.
ISO Tolerance Grade
Shaft and bore features can be machined to IT6/IT7-level precision classes for precise press, slip and transition fits against mating components.
Surface Roughness
Fine turning, polishing and electropolishing deliver smooth sealing faces and thread surfaces; mirror-level finishes are achievable on stainless steel fittings.
Concentricity and Runout
Coaxiality, circular runout and total runout between thread axis, bore and outer diameter are tightly controlled to prevent eccentric assembly and leakage.
Thread Pitch Diameter
Pitch diameter, thread depth and taper are verified with GO / NO-GO plug and ring gauges so internal and external threads assemble at the designed engagement.
Perpendicularity of Sealing Face
Shoulder faces and sealing surfaces are machined square to the thread axis, giving even gasket or O-ring compression and avoiding point-loading leaks.
Deburring and Edge Quality
Controlled chamfers, radiused transitions and complete deburring protect O-rings and seals during assembly and eliminate loose particles in fluid passages.
Inspection Documentation
Critical dimensions, thread gauging results and surface checks can be recorded per batch, with first-article inspection for new custom threaded fitting designs.
Machining Processes and Strict Quality Testing
Custom threaded fittings are produced on CNC turning and CNC milling equipment, then verified through thread gauging, optical profile measuring and coordinate measuring. Every production lot passes strict quality testing before shipment.
CNC Milling
3-axis and 4-axis CNC milling machines wrench flats, cross-holes, port cavities, flange patterns and complex fitting bodies that turning alone cannot produce.
CNC Turning
Precision CNC turning and single-point threading cut internal and external threads, tapers, bores and sealing surfaces with high repeatability across the batch.
2D Projector Measuring
An optical profile projector magnifies the thread outline for direct comparison against the drawing profile, checking tooth form, taper, crest and root geometry.
CMM Testing
A coordinate measuring machine verifies diameters, positions, perpendicularity, concentricity and complex spatial dimensions against the nominal drawing values.
Digital 2D Optical Profile Measuring for Thread Profiles
Thread form cannot be judged from outer dimensions alone. Our digital 2D profile projector projects a magnified silhouette of the machined thread onto a measuring screen, allowing inspectors to overlay the actual crest, root, flank angle and taper against the theoretical profile from the drawing — an essential check for both standard NPT/BSP threads and custom non-standard thread forms.
The full quality testing routine for CNC machined threaded fittings combines the checks below, selected according to drawing requirements and application criticality:
- GO / NO-GO thread plug and ring gauge testing
- 2D optical profile projection of thread tooth form
- CMM coordinate measurement of critical dimensions
- Surface roughness testing on sealing surfaces
- Concentricity and runout inspection
- Hardness and material verification when specified
- Visual and burr inspection under magnification
- Hydrostatic / air pressure testing when required
From a Single Prototype to Large-Batch Production
Custom CNC machined threaded fittings are available at every order quantity. Tooling paths, gauges and inspection plans are carried over from prototype to serial production, so parts remain identical as volumes grow.
Single Piece and Prototype
One-off machined fittings, design validation samples, repair and replacement parts for obsolete equipment, and first-article samples built directly from the drawing or reverse-engineered sample.
Small-Batch Production
Pilot runs and small batches for machine builders, engineering projects and maintenance stock, with fast setup and the same gauge-based thread control used on large orders.
Medium Serial Production
Recurring batches with optimized fixturing, consistent cycle times, batch inspection records and stable material supply for ongoing product assembly lines.
Large-Volume Mass Production
High-volume CNC production with multi-machine capacity, standardized workholding, statistical process control and lot traceability for long-term demand.
Materials for Custom CNC Machined Threaded Fittings
The material of every custom threaded fitting is selected per drawing and application — corrosion resistance, pressure rating, temperature, weight, media compatibility and cost all considered. The twelve groups below cover the majority of industrial fitting requirements.
Stainless Steel 304 / 304L
General-purpose corrosion resistance for plumbing, instrumentation and general industrial threaded fittings.
Stainless Steel 316 / 316L
Mo-bearing stainless for chemical, marine, food and medical-related fluid environments.
Carbon Steel
High-strength machinable steel for hydraulic and mechanical fittings, with plating or black oxide as specified.
Alloy Steel 4140 / 4130
Heat-treatable alloy steel for high-pressure threaded adapters subject to heavy mechanical loads.
Brass C36000 / C37700
Free-machining brass for pneumatic fittings, quick connectors, gas and water components.
Bronze / Copper
Bronze and copper threaded fittings for seawater, electrical grounding and legacy-equipment replacement.
Aluminum 6061 / 7075
Lightweight anodized CNC machined threaded fittings for aerospace, robotics and weight-sensitive assemblies.
Titanium Grade 2 / Grade 5
High strength-to-weight and corrosion resistance for aggressive media and demanding engineering use.
Duplex / Super Duplex
High-strength stainless grades for chloride, offshore and heavy chemical-process applications.
Inconel / Hastelloy / Monel
Nickel-based super alloys for extreme temperature, acidic and high-corrosion threaded fitting applications.
PEEK / PVDF / PTFE
High-performance engineering plastics for insulating, chemical-resistant and lightweight threaded fittings.
Nylon / Delrin (POM)
Tough dimensionally stable polymers for light-duty pneumatic, electronic and consumer-equipment fittings.
A Complete Custom Threaded Fittings Machining Service
Custom Machined Threaded Fittings Built Around Your Design
As a custom threaded fittings manufacturer, we produce CNC machined threaded fittings that follow the drawing exactly: custom material, custom dimensions, custom thread type and custom surface treatment. Whether the requirement is a stainless steel NPT thread coupling, a brass BSPP quick connector, a CNC machined hydraulic pipe fitting with SAE O-ring boss threads, or a 304 stainless four-way cross fitting, the part is machined to the geometry, tolerance and finish your equipment demands.
Our service is particularly valued where catalogue parts do not fit: mixed thread ends, special thread length, unusual hex or shoulder geometry, non-standard taper, modified crest and root dimensions, left-hand or multi-start threads, and threads reverse-engineered from an old sample. Standard profiles such as NPT, NPTF, BSPP, BSPT, metric and UN/UNF are machined with gauge verification, while completely non-standard thread forms are cut directly from the profile defined on your drawing.
Every CNC machined stainless steel threaded fitting, brass threaded connector, aluminum threaded adapter or plastic threaded insert benefits from the same workflow: drawing review, process planning, CNC turning, CNC milling, deburring, surface treatment, thread gauging, 2D optical profile measuring and CMM dimensional inspection before packing.
Precision, Surface Quality and Repeatable Supply
High-precision threaded fittings require more than a correct nominal size. We control pitch diameter, taper rate, flank angle, crest and root condition, coaxiality, sealing-face perpendicularity and surface roughness together, so the finished fitting assembles smoothly, seals reliably and performs under pressure. Fine machining delivers smooth thread surfaces from Ra 0.2 micrometre class finishes upward, and optical / coordinate measuring confirms the result to micrometre-level resolution.
Order quantities are equally flexible: a single CNC machined prototype, a small custom batch for a machine build, recurring serial production or large-batch mass production all run on the same process standards, with tooling, gauges and inspection data retained so repeat orders match the original parts. This makes the service suitable both for maintenance and reverse-engineering work and for OEM supply lines.
Send the drawing, specification or physical sample of the threaded fitting to be customized — including the required material, thread standard or non-standard thread profile, dimensions, taper, crest and root requirements, surface treatment and quantity — and the fitting will be CNC machined precisely per drawing, from first prototype to full production volume.