Gyrolok® (Hoke) Tube-Fitting Cross-Reference: Crestflo Interchange & Equivalents
A Gyrolok® cross-reference tells you exactly which Crestflo instrumentation tube fitting matches a given Gyrolok® twin-ferrule fitting in dimensions, so an engineer or buyer can source that same connection in stainless steel or an exotic alloy without touching the tubing run design. Crestflo's double-ferrule and single-ferrule fittings are built as a drop-in dimensional match for Gyrolok® fittings, and each one is qualified to ASTM F1387, the compression-tube-fitting standard that takes the risk out of substitution. Send in your Gyrolok® part list, and you'll get back a Crestflo interchange complete with material test certificates. Standard items ship from stock; specials are made to order, with delivery running 6-8 weeks.
Crestflo parts referenced here are listed as independent dimensional interchange equivalents, not genuine Gyrolok® parts. Gyrolok® is a registered trademark of Hoke, Inc., a CIRCOR International company, and Crestflo has no affiliation with, sponsorship from, or endorsement by Hoke or CIRCOR. This cross-reference covers instrumentation-grade stainless-steel and alloy compression tube fittings only; it doesn't extend to copper or plumbing compression fittings. It's limited to the Gyrolok® fitting line specifically. For Hoke valves, see the Hoke cross-reference.
What Is a Gyrolok® Fitting? Twin-Ferrule Instrumentation Tube Fittings by Hoke
Gyrolok® is the twin-ferrule, or double-ferrule, line of instrumentation compression tube fittings made by Hoke, Inc., a CIRCOR International brand. The design grips and seals tubing using a front ferrule and a back ferrule, both driven onto the tube's outside diameter by a threaded nut. The result is a leak-tight, gauge-verifiable mechanical connection suited to instrumentation, process, and analytical service. Sizes run fractional and metric, and the Gyrolok® family covers unions, male and female connectors, elbows, tees, crosses, reducers, adapters, caps, plugs, bulkhead unions, and port connectors.
"Hoke Gyrolok" and "Circor Gyrolok" name the same product line. So a true equivalent can't just look like the fitting, it has to match the tube-OD envelope, the nut, and the ferrule geometry down to the details. Crestflo builds every interchange on that standard.
Also Known As: Gyrolok Designations and Common Search Terms
Buyers ask for these fittings under a range of names, and a proper cross-reference has to account for all of them. Gyrolok® fittings show up as Gyrolok tube fittings, Gyrolok compression fittings, Gyrolok twin-ferrule fittings, and Gyrolok double-ferrule fittings. Some call them Hoke Gyrolok fittings; others say Circor Gyrolok fittings. When buyers are second-sourcing the line, the request takes different shapes too: a Gyrolok interchange, a Gyrolok equivalent, a Gyrolok alternative, a Gyrolok replacement, or a Gyrolok part number cross-reference. More often than not, they want the chart as a PDF. No matter which phrasing arrives, it points to the same Crestflo interchange laid out below. A full part-level cross-reference in PDF form is available on request.
How the Crestflo–Gyrolok Interchange Works: Dimensional Equivalence, Not Intermixing
Crestflo builds the equivalent part as a complete, all-Crestflo fitting. The double-ferrule geometry matches the tube-OD, nut and ferrule envelope of the Gyrolok® part, so the Crestflo fitting goes onto the same tube size and mates with the same thread and end connection. It's a part-for-part dimensional interchange. Swap a Gyrolok® union for a Crestflo union, a Gyrolok® male connector for a Crestflo male connector, and so on.
Crestflo ferrules and nuts stay with Crestflo fittings, and Gyrolok® ferrules stay with Gyrolok® fittings. Combining the two brands within a single connection isn't allowed. Crestflo makes both single and double ferrule designs, and its hardened and non-hardened ferrules are available to match specific requirements. Curious why brands shouldn't be mixed in one joint? The engineering rationale is laid out in the guide on mixing tube-fitting brands.
Gyrolok Fitting Configurations and the Crestflo Interchange Equivalent
This table lines up every Gyrolok® twin-ferrule configuration with its matching Crestflo instrumentation tube fitting. None of the Gyrolok® part numbers here are made up. The verified part-level chart, PDF included, comes through the RFQ, so each number gets confirmed rather than guessed at.
| Gyrolok fitting configuration | Crestflo interchange equivalent | Interchange basis |
|---|---|---|
| Tube-to-tube union | Union tube fitting | Dimensional; ASTM F1387 qualified |
| Male connector (to NPT/BSP) | Male connector | Dimensional; ASTM F1387 qualified |
| Female connector | Female connector | Dimensional; ASTM F1387 qualified |
| Union elbow / male elbow | Elbow tube fitting | Dimensional; ASTM F1387 qualified |
| Union tee / branch tee | Tee tube fitting | Dimensional; ASTM F1387 qualified |
| Nut and ferrule sets | Nut and ferrule · ferrules | Dimensional; ASTM F1387 qualified |
Sizes run all the way up to 2" (50 mm) in tube OD. That covers both imperial fractional options (1/8", 1/4", 3/8" and 1/2") and metric options (6 mm, 8, 10 and 12 mm). Crestflo backs that up with a wide range of end and thread options: NPT per ASME B1.20.1, BSPT, BSPP, ISO-parallel, JIC-37°, SAE-ORB, socket-weld and butt-weld. Values follow the applicable standard in each case, and it's all customizable to your requirement.
ASTM F1387: The Performance Basis Behind the Gyrolok Equivalent
Most substitutions get vetoed over one question: does the alternative actually perform like the original? Crestflo's answer is ASTM F1387, the performance-qualification standard for mechanically attached fittings on metallic tubing. To qualify under F1387, a fitting goes through a defined regime of gas leakage, hydrostatic proof, burst, impulse, rotary-flexure fatigue, vibration, thermal-cycling and tensile (pull-out) testing. That's the evidence a specification engineer needs before signing off on a second source. Crestflo compression tube fittings are tested per ASTM F1387; the standard itself is available on the ASTM F1387 reference page. Every part carries a heat/lot number, and EN 10204 3.1 material test certificates come standard, with 3.2 available on request.
Gyrolok Equivalent Alloys: 316/316L Plus Exotic and Sour-Service Grades
Alloy breadth is often the point where a Gyrolok® cross-reference turns into a decision to switch. Crestflo's core strength lies in the corrosion-resistant grades that carry long lead times from the major suppliers. Standard interchange material is 316/316L. The exotic and duplex range goes well past that.
| Alloy family | Representative grades | Typical driver | Material reference |
|---|---|---|---|
| Austenitic stainless | 316/316L, 304/304L, 904L | General instrumentation service | 316/316L |
| Duplex / super-duplex | 2205, Super Duplex 2507 | Chloride & offshore | Super Duplex 2507 |
| Nickel, Hastelloy | C-276, C-22, B-2, B-3, X | Aggressive acids, sour service | Hastelloy C-276 |
| Nickel, Inconel/Monel | Inconel 625, 825, Monel 400 | High temperature, seawater | Inconel 625 · Monel 400 |
| Super-austenitic / titanium | 254 SMO, AL-6XN, Alloy 20, Titanium Gr2 | Halides, oxidisers | Alloy pages |
Sour-service interchange is available in NACE MR0175 / ISO 15156-compliant material. Composition, PREN and mechanicals follow the applicable material standard, and can be tailored to requirement.
How to Cross-Reference Your Gyrolok Part Numbers
Send your Gyrolok® catalog part numbers, or a full bill of materials, to Crestflo. Our engineering team returns a Crestflo interchange list covering configuration, size, thread, alloy and finish, along with the material test certificates for each line. A genuine part-for-part match can't be guessed at; it has to be verified. That's why exact Gyrolok®-to-Crestflo numbers are confirmed per request rather than published as a static chart. An interactive lookup is also available through the cross-reference tool. Email sales@crestflousa.com or call +1 346 594 9005 (Houston, TX), and request your Gyrolok cross-reference.
Why Crestflo for Your Gyrolok Interchange
Crestflo is the instrumentation arm of a Government-of-India-recognized export house with four decades behind it and a solid delivery record across the Middle East. Manufacturing capability sits at the core, built to support a focused, US-facing brand and to serve as a dependable second-source supplier for the Gyrolok® line. Confidence gets engineered into every interchange.
| Capability | Crestflo |
|---|---|
| Ferrule design | Single and double ferrule; hardened and non-hardened |
| Size range | Tube OD up to 2" (50 mm), imperial fractional and metric |
| Performance basis | Tested per ASTM F1387 |
| Traceability | Heat/lot number on every part; EN 10204 3.1 MTC standard, 3.2 on request |
| Certifications | ISO 9001 / 14001 / 45001 & PED certified |
| Lead time | Ready stock for standard items · made-to-order for specials · 6–8 week delivery |
| Origin | Indian origin; US / European melt available on request, with full material traceability |
| Programs | Small MOQ; private label; distributor line card |
End users and MRO buyers can request a quote. Distributors should request the line card, and OEMs are welcome to discuss the private-label program. Material origin and TAA/DFARS status appear plainly on the US-origin compliance page; full traceability documentation lives on the traceability page, maintained by Crestflo.
Related Cross-References and Multi-Brand Interchange
For brand-level second-sourcing beyond the Gyrolok® fitting line, check the Hoke cross-reference, the Hoke alternative, and Hoke vs Crestflo. Need to swap a Gyrolok fitting for Swagelok or Parker CPI? That's handled on the Swagelok cross-reference, the Parker CPI cross-reference, and the master interchange chart. Every cross-reference starts at the tube-fitting cross-reference hub. All interchange equivalents ship from the tube-fittings product line.
Frequently Asked Questions: Gyrolok Cross-Reference
What is a Gyrolok fitting?
Gyrolok® is a twin-ferrule, or double-ferrule, instrumentation compression tube fitting made by Hoke, Inc., a CIRCOR International brand. Two ferrules do the work: front and back, drawn onto the tube's outer diameter by a threaded nut. That's what grips and seals the metallic tubing.
Does Crestflo make a Gyrolok equivalent?
Yes, that's correct. Crestflo builds its instrumentation tube fittings as dimensional interchange equivalents to Gyrolok® fittings, and each one is qualified to ASTM F1387. These are independent Crestflo parts, sold as interchange equivalents. They aren't genuine Gyrolok® parts.
Can I mix Crestflo and Gyrolok ferrules or nuts in the same joint?
No. Stick to all-Crestflo components in a Crestflo fitting. Interchange means swapping one complete fitting for another, part for part, not mixing brands within a single connection. For the engineering reason behind this, check the guide on mixing tube-fitting brands.
What proves the Crestflo fitting performs like the Gyrolok one?
Crestflo tests to ASTM F1387, the standard governing performance qualification for compression tube fittings. F1387 checks leakage, hydrostatic proof, burst, impulse, fatigue, vibration, thermal cycling and pull-out. Quite a list. That's what gives the substitution its documented performance basis.
What sizes and threads are available for the interchange?
Tube outside diameter runs up to 2 inches (50 mm), spanning imperial fractional sizes and metric ones too, including 6, 8, 10, and 12 mm, plus more besides. End options cover NPT, BSPT, BSPP, ISO-parallel, JIC-37°, SAE-ORB, socket-weld, and butt-weld. Values follow whichever standard applies, and the whole lot can be customized to what the job requires.
Which alloys can I get that may be hard to source in Gyrolok?
316 and 316L come standard, but the shop also stocks 904L, Duplex 2205, Super Duplex 2507, 254 SMO, AL-6XN, Alloy 20, Inconel, Monel, Hastelloy, Nickel 200/201 and Titanium Gr2. For sour service, material compliant with NACE MR0175 / ISO 15156- is available too.
How do I cross-reference my Gyrolok part numbers?
Send Gyrolok® catalog part numbers or a bill of materials to sales@crestflousa.com. You'll get back the Crestflo interchange list along with material test certificates. Exact part-for-part matches get verified per request; they aren't published as a static table.
What is the lead time compared with Gyrolok?
Standard items ship from ready stock. Specials are made to order, with delivery running 6 to 8 weeks. That's well ahead of the major brands, who often need 20-plus weeks on exotic alloys.
Is Crestflo affiliated with Hoke or CIRCOR?
No, it isn't. Gyrolok® is a registered trademark belonging to Hoke, Inc. Crestflo operates as an independent manufacturer, with no affiliation to, sponsorship from, or endorsement by Hoke or CIRCOR.
Are the fittings made in the USA?
No. Crestflo serves the US market, though its standard product comes from India. US or European melt is available on request, backed by full material traceability. That traceability is what makes TAA/DFARS review possible when domestic melt is required.
Do the parts come with traceability?
Yes. Every part carries a heat/lot number. EN 10204 3.1 material test certificates come as standard, and we can supply 3.2 on request. Positive material identification (PMI) is also available.