TES-LOK Tube Adapter Tube Fittings — convert compression tube ends to any thread standard: NPT · BSP · SAE · MS · UNF · ISO. Male adapter · Female adapter · SAE/MS straight thread adapter. SS 316 · Brass · Monel · Inconel · Up to 6,000 PSI · ISO 9001:2015 certified.
Tube Adapters Range
Male Adapter
Female Adapter
SAE/MS Straight Thread Adapter
A tube adapter tube fitting is a conversion fitting that connects a double-ferrule compression tube end to a different thread standard or thread system. While standard tube fitting connectors (male connector, female connector) interface with the most common piping thread systems (NPT, BSP), tube adapters extend the compatibility of the compression tube system to hydraulic, automotive, aerospace, and industrial equipment thread standards that use different thread profiles, pitch, and sealing methods — including SAE straight thread (J1926), MS straight thread (MIL-spec), JIC 37° flare, UNF, and ISO metric threads.
The defining characteristic of a tube adapter — compared to a connector — is its role as a standard-crossing fitting: it bridges two thread worlds. This is especially important on skid-mounted process equipment, hydraulic power units, and mobile or offshore installations where process instrumentation (NPT/BSP compression tube systems) must interface with hydraulic equipment (SAE/MS straight thread systems) without using additional hex nipples or thread-to-thread adapters in series.
| Adapter Type | Compression End | Thread End | Thread Sealing Method | Typical Application |
|---|---|---|---|---|
| Male Adapter | Double-ferrule compression tube | Male external thread — NPT, BSPT, BSP, UNF | PTFE tape / anaerobic sealant on male thread (NPT/BSPT); bonded seal for BSPP female port | Compression tube to female-threaded equipment port — process gauge, manifold, valve body |
| Female Adapter | Double-ferrule compression tube | Female internal thread — NPT, BSPT, BSP, UNF | PTFE tape on mating male thread (NPT/BSPT); bonded seal on mating male BSPP shoulder | Compression tube to male-threaded equipment stud or nipple — instrument process stubs, manifold male ports |
| SAE/MS Straight Thread Male Adapter | Double-ferrule compression tube | Male UNF straight thread (SAE J1926 / MS16142) + O-ring | O-ring on male thread shoulder seats on chamfered face of SAE female port — no PTFE | Instrument tube to SAE straight-thread hydraulic ports — hydraulic power units, actuators, mobile equipment, offshore BOP systems |
| SAE/MS Straight Thread Female Adapter | Double-ferrule compression tube | Female UNF straight thread with O-ring face seal (SAE J1926) | O-ring on mating male thread shoulder; flat-face O-ring seal at port face | Compression tube to male SAE straight-thread stubs on hydraulic components |
| Reducing Adapter | Double-ferrule compression tube (larger OD) | Male or female thread (smaller size) — or smaller compression tube OD | Per thread type above | OD step-down or step-up at a thread connection without separate reducing fitting |
| Feature | NPT (Tapered Pipe Thread) | SAE/MS Straight Thread (UNF + O-ring) |
|---|---|---|
| Thread form | Tapered — thread OD increases toward shoulder | Parallel — constant OD throughout thread length |
| Sealing mechanism | Thread flank interference on taper + PTFE/sealant | O-ring compressed on chamfered seat at port face |
| Sealant | PTFE tape (2–3 wraps) or anaerobic thread sealant | O-ring only — no PTFE, no thread sealant |
| Re-usability | Limited — each PTFE remake degrades seal quality | High — O-ring replacement restores seal without thread damage |
| Common standards | ASME B1.20.1 (NPT), BS 21 (BSPT) | SAE J1926, MS16142, ISO 11926 |
| Industries | Process piping, instrumentation, chemical | Hydraulic systems, mobile equipment, aerospace, offshore |
| TES-LOK Tube Adapter Tube Fitting — Specifications | |
|---|---|
| Brand | TES-LOK (by Tesco Steel & Engineering) |
| Compression end | Double-ferrule bite-type (TES-LOK) — all adapter types |
| Thread end options | Male NPT · Female NPT · Male BSP (BSPP/BSPT) · Female BSP · SAE J1926 male/female · MS16142 · UNF · ISO metric |
| Tube OD range | 1/16" – 1" (imperial) · 3 mm – 25 mm (metric) |
| Thread size range | 1/16" NPT – 3/4" NPT · 1/16" BSP – 3/4" BSP · SAE -2 to -20 ports · UNF 7/16–1-5/16" |
| SAE O-ring materials | Buna-N (Nitrile) standard · Viton (FKM) · EPDM · PTFE-encapsulated |
| Body materials | SS 316 / 316L (standard) · SS 304 · Brass · Monel 400 · Inconel 600 · Hastelloy C-276 |
| Max. working pressure | 6,000 PSI (SS 316) · 3,000 PSI (Brass) · SAE port rating as per O-ring and port size |
| Temperature range | −196°C to +400°C (SS) · −29°C to +260°C (Brass) |
| Standards | ASTM D1710 · ASTM D3294 · SAE J1926 · MS16142 · ISO 11926 |
| Certifications | ISO 9001:2015 · EN 10204 3.1 MTC available |
| Compatible compression systems | TES-LOK · Swagelok · Parker A-LOK · Ham-Let |
A TES-LOK tube adapter connects a compression tube system directly to SAE, MS, UNF, ISO, NPT, or BSP equipment threads without a chain of intermediate hex nipples and adapters. Each intermediate fitting is an additional potential leak joint and assembly error point. A single tube adapter reduces this to one fitting, one seal, one installation step.
TES-LOK SAE/MS straight thread tube adapters integrate the compression tube end with an O-ring sealing male or female UNF thread — the same thread system used in hydraulic power units, offshore BOP systems, and mobile equipment. This allows instrument tubing to connect directly to hydraulic ports without a separate compression-to-hydraulic adapter in the tube run.
TES-LOK tube adapters are available with any combination of metric compression tube OD (6 mm, 8 mm, 10 mm, 12 mm, etc.) and imperial or metric thread (NPT, BSP, UNF, ISO metric). Essential when European-supplied instruments with metric tube connections must interface with American NPT-threaded process equipment, or when metric hydraulic equipment must connect to imperial tube systems.
The compression end of every TES-LOK tube adapter uses the same double-ferrule bite-type mechanism as all other TES-LOK tube fittings — 1¼ turns from finger-tight on initial make-up, back to the original mark on remakes. No special tools, no pre-flaring, no soldering. Field technicians familiar with TES-LOK tube fittings can make up adapter connections with zero additional training.
Available in SS 316/316L (standard), Monel 400, Inconel 600, and Hastelloy C-276, with matching CRA ferrules. O-rings for SAE adapters in Buna-N (standard), Viton (FKM) for hydrocarbon and high-temperature, EPDM for steam and hot water service. EN 10204 3.1 MTCs and PMI available for all CRA grades.
Manufactured under ISO 9001:2015 quality management system. Each adapter is hydrostatic pressure-tested at 1.5× working pressure before dispatch. Full material traceability from raw material heat to finished fitting is maintained under the TES-LOK quality system.
▶ What is a tube adapter tube fitting?
A tube adapter tube fitting is a conversion fitting that connects a double-ferrule compression tube end to a different thread standard or system — such as SAE straight thread, MS, UNF, ISO metric, NPT, or BSP — in a single fitting body without intermediate adapters. Used wherever instrument or process tubing must interface with equipment using a thread standard not covered by standard male or female connectors.
▶ What is the difference between a tube adapter and a tube connector?
A connector (male or female connector) interfaces with the standard NPT or BSP thread systems used in process piping. A tube adapter typically refers to fittings that cross into other thread systems — SAE/MS straight thread, UNF, ISO metric, JIC 37° — or provide specific sealing mechanisms (O-ring face seal) not available in standard connectors. In practice, male and female adapters for NPT/BSP overlap with standard connectors; the distinction becomes important for SAE/MS and hydraulic thread systems.
▶ What is an SAE/MS straight thread tube adapter?
An SAE/MS straight thread tube adapter connects a compression tube end to an SAE J1926 or MS16142 straight thread hydraulic port. The straight thread does not seal by thread interference — it clamps the O-ring on the male thread shoulder against the chamfered seat of the SAE female port. No PTFE tape is used; sealing is by O-ring only.
▶ Can I use PTFE tape on an SAE/MS straight thread adapter?
No. Never use PTFE tape on SAE/MS straight thread adapters. The parallel thread does not seal on PTFE — sealing is exclusively by the O-ring on the thread shoulder. PTFE tape prevents the O-ring from seating correctly and causes leaks. Replace the O-ring at every reassembly if it shows any deformation or damage.
▶ What tube adapter types does TES-LOK manufacture?
Male Adapter (compression tube to male NPT/BSP/SAE/UNF external thread), Female Adapter (compression tube to female NPT/BSP socket), SAE/MS Straight Thread Male and Female Adapter (with O-ring for hydraulic ports), and Reducing Adapter (different tube OD to different thread size). All available in equal and reducing configurations.
▶ Can tube adapters connect metric tube OD to NPT threads?
Yes. TES-LOK tube adapters are available with metric tube OD (6 mm, 8 mm, 10 mm, 12 mm, etc.) on the compression end and NPT, BSP, or SAE threads on the thread end. Essential for connecting European metric-tube instruments to American NPT-threaded process equipment without additional reducing fittings in the tube run.
▶ What is the maximum pressure rating for TES-LOK tube adapters?
Up to 6,000 PSI in SS 316 at ambient temperature. Brass to 3,000 PSI. SAE/MS adapter pressure is also governed by the O-ring type and SAE port size — verify O-ring pressure rating for the specific SAE port and service conditions.
▶ What materials are available for tube adapter tube fittings?
SS 316 (standard), SS 316L, SS 304, Brass, Monel 400, Inconel 600, and Hastelloy C-276. O-rings in Buna-N (standard), Viton, EPDM, or PTFE-encapsulated for SAE adapters. EN 10204 3.1 MTCs and PMI available on request.
Male · Female · SAE/MS Straight Thread · Reducing · SS 316 · Brass · CRA · NPT · BSP · SAE · UNF · Up to 6,000 PSI
ISO 9001:2015 · EN 10204 3.1 MTC · Fast delivery worldwide