Ham-Let vs Crestflo: Instrumentation Fittings & Valves Compared
This page puts Ham-Let up against Crestflo, two suppliers of instrumentation hardware. Ham-Let is the established brand behind the Let-Lok twin-ferrule tube fitting, along with its needle, ball, manifold and bleed valves. Crestflo serves the US market and builds twin-ferrule fittings performance-qualified to ASTM F1387 for dimensional interchange. Its catalog also covers instrumentation valves and tubing, ranging from 316/316L through high-nickel and titanium alloys. Standard items ship from stock; specials are made to order, with delivery running 6-8 weeks. Below, we compare the two suppliers on interchange basis, alloys, certifications, traceability and lead time, and we'll show you how to request a Ham-Let / Let-Lok cross-reference.
Scope note: "ferrule" here means a fluid-system compression ferrule, not an electrical or wire ferrule. "Needle valve," "ball valve" and "manifold" are instrumentation terms as well; they aren't plumbing, carburetor or exhaust parts.
Trademark & affiliation: Ham-Let® and Let-Lok® are registered trademarks of the Ham-Let Group of companies. Crestflo is a separate, independent manufacturer and isn't affiliated with, endorsed by, or a licensee of Ham-Let. On this page, "interchange" simply means the parts match in dimension. Nothing more. It doesn't mean Crestflo's parts are compatible with, or can be mixed with, genuine Ham-Let components.
What Is Ham-Let (and the Let-Lok Tube Fitting)?
Ham-Let makes instrumentation fittings and valves, and its twin-ferrule (double-ferrule) tube fitting sells under the name Let-Lok®. There's a related compression line too, called One-Lok®. The lineup spans twin-ferrule tube fittings, instrumentation valves (needle, ball, check, manifold and bleed), plus the pipe and weld fittings that go with them. The Ham-Let Group of companies supplies all of these Ham-Let® instrumentation products. When specifiers search "who makes Ham-Let fittings," "ham let fittings," "let-lok fittings" or "hamlet fittings," they're all pointing at this same twin-ferrule product family. That's the reference point for the comparison below.
Crestflo is the instrumentation division of an export house with four decades behind it, one recognized by the Government of India and with a solid delivery record across the Middle East. It builds twin-ferrule fittings, valves and tubing for instrumentation work. These are engineered as dimensional equivalents to the major twin-ferrule systems on the market, including Ham-Let / Let-Lok.
Also Known As: Ham-Let, Let-Lok, One-Lok & Related Designations
Ham-Let comes up under a handful of names, and buyers should recognize the equivalent products no matter which one they search. You'll see "Ham Let" or "Ham-Let Group" written out in full. The twin-ferrule fitting shows up as Let-Lok, sometimes "Let Lok," sometimes just "ham-let let-lok." The compression line goes by One-Lok, or "one lok" in lowercase searches. Other common phrasings include Ham-Let tube fittings, Ham-Let compression fittings, Ham-Let twin-ferrule and double-ferrule fittings, and Ham-Let instrumentation fittings. The valve families follow the same pattern: Ham-Let needle valve, ball valve, manifold valve, bleed valve. UNS and Werkstoff alloy numbers belong to the material side of things, not the brand name, and you'll find those covered on the Crestflo material pages linked below.
Ham-Let vs Crestflo at a Glance: Comparison Table
The table comparing Crestflo and Ham-Let below sticks to the facts, with no spin either way. Any cell that would require asserting a Ham-Let specification just reads "see manufacturer": Crestflo won't publish or claim a competitor's ratings, pricing, or lead times.
| Attribute | Ham-Let (as published by the manufacturer) | Crestflo |
|---|---|---|
| Product scope | Twin-ferrule tube fittings, instrumentation valves, manifolds | Twin-ferrule tube fittings, instrumentation valves, manifolds, tubing |
| Ferrule design | Twin (double) ferrule | Twin (double) and single ferrule; hardened and non-hardened to requirement |
| Interchange basis (fittings) | See manufacturer | Dimensional interchange, performance-qualified to ASTM F1387 |
| Valve qualification basis | See manufacturer | Valves designed and qualified to ASME B16.34 / API 6D / 598 / 602 as applicable |
| Alloy range | See manufacturer | 304/304L, 316/316L, 904L; Duplex 2205, Super Duplex 2507, 254 SMO, AL-6XN, Alloy 20; Inconel, Incoloy, Monel, Hastelloy, Nickel 200/201; Titanium Gr 2 |
| Fitting size range | See manufacturer | Compression tube fittings up to 2" (50 mm) OD |
| Valve size range | See manufacturer | 1/16" to 1", threaded or tube-fitting ends |
| Sizing system | See manufacturer | Both imperial and metric on all fittings |
| Traceability | See manufacturer | Heat/lot number on every part; EN 10204 MTC 3.1 standard, 3.2 on request |
| Sour-service (NACE) | See manufacturer | NACE MR0175 / ISO 15156 in appropriate alloys |
| MOQ / private label | See manufacturer | Small MOQ; private-label and made-to-print available |
| Lead time | See manufacturer | Ready stock for standard items · made-to-order for specials · 6-8 week delivery |
| Country of origin | See manufacturer | Indian origin; US / European melt available on request, with full material traceability |
Is Crestflo Interchangeable With Ham-Let / Let-Lok?
Crestflo twin-ferrule fittings are built as dimensional equivalents to major twin-ferrule systems, a geometry-for-geometry replacement of the ferrule, nut and body envelope. Not a "compatible," "intermix" or "genuine" part. What makes that interchange claim objective and non-branded is ASTM F1387, the compression-tube-fitting performance qualification standard against which Crestflo fittings are tested. F1387 is a published qualification standard, not a marketing label, and that's precisely why it lets a Ham-Let / Let-Lok user weigh a second source on facts rather than sales talk. The ASTM F1387 interchange qualification page lays out the methodology.
It's worth noting that F1387 is a fitting standard. Crestflo instrumentation valves are designed and qualified against the standards that apply to valves: ASME B16.34 and the relevant API methods. Not F1387.
Crestflo won't hand you some invented Ham-Let-to-Crestflo part-number table. There isn't one. Send over your Ham-Let / Let-Lok catalog numbers instead, and the engineering team will return a verified dimensional-equivalent mapping. Request your Ham-Let / Let-Lok cross-reference, or start an RFQ. Want to understand the ferrule mechanics behind interchange? See single vs double ferrule.
Interchange Scope by Product Family
Interchange gets mapped by family and geometry, not by guessing at a part number:
| Ham-Let / Let-Lok family | Crestflo dimensional-equivalent product | Interchange basis |
|---|---|---|
| Let-Lok twin-ferrule tube fittings | Twin-ferrule tube fittings | ASTM F1387 qualification |
| Instrumentation needle valves | Needle valves | ASME B16.34 / API as applicable |
| Instrumentation ball valves | Ball valves | ASME B16.34 / API as applicable |
| Valve manifolds (2/3/5-way) | Valve manifolds | ASME B16.34; 100% seat & shell leak tested |
Alloys: 316L Through Hastelloy, Inconel & Titanium
Alloy breadth is what sets this apart from a standard 316 catalog. Crestflo doesn't stop at stainless; it supplies Ham-Let-equivalent geometries across duplex, super-austenitic, nickel and titanium grades too:
| Alloy family | Grades | Reference |
|---|---|---|
| Stainless | 304/304L, 316/316L, 904L | 316/316L, 904L |
| Duplex / super-austenitic | Duplex 2205, Super Duplex 2507, 254 SMO, AL-6XN, Alloy 20 | Super Duplex 2507 |
| Nickel | Inconel 600/601/625/718/825, Incoloy 800/800H/825, Monel 400/K500, Hastelloy C-276/C-22/B-2/B-3/X, Nickel 200/201 | Hastelloy C-276, Inconel 625 |
| Titanium | Titanium Gr 2 | Titanium Gr 2 |
Alloy composition and mechanical properties follow the relevant ASTM material standards. Values track whatever standard applies, and they're adjustable to meet specific requirements.
Certifications, Testing & Traceability
Crestflo holds ISO 9001, 14001, and 45001 certification, along with PED compliance. Its fittings are performance-qualified to ASTM F1387, and where alloys call for it, they meet sour-service requirements under NACE MR0175 / ISO 15156. Certificate copies live in the quality library. They aren't numbered on content pages.
- Traceability: every part carries a heat/lot number, and each one ships with an EN 10204 MTC 3.1 certificate as standard; 3.2 is available on request. See material test certificate & traceability.
- Testing regime: parts go through hydraulic proof, burst and impulse testing, plus pneumatic, flexure fatigue, rotary flex, vibration, thermal cycling, pull-out, vacuum, and positive material identification (PMI) checks. Every manifold gets a 100% seat and shell leak test.
- Verification: NDT is done in-house. Destructive testing runs at ISO/IEC 17025-accredited laboratories, and third-party inspection can be arranged on request.
We don't publish datasheets or CAD files for public download. Customers can request them directly.
Lead Time & Cost vs a Ham-Let Order
Crestflo keeps standard items in stock, builds specials to order, and delivers in 6-8 weeks. Compare that to the 20+ weeks typical of the major twin-ferrule brands. Small MOQ is available. Landed cost holds up well even after US duties and tariffs. Crestflo won't quote a competitor's price or lead time; that's the manufacturer's call to make. See tube fitting lead time and the lead-time & post-tariff cost benchmark for the numbers behind this.
Where Ham-Let Fits Among Swagelok, Parker & Other Twin-Ferrule Brands
Ham-Let belongs to a small group of established twin-ferrule instrumentation brands that also includes Swagelok, Parker, Hy-Lok, Hoke, Fitok and DK-Lok. Consider the "Ham-Let vs Swagelok" comparison: it hinges on dimensional fit and F1387 qualification, not brand loyalty. The same second-source reasoning holds across the category, whether you're buying direct or going through a Ham-Let distributor. See Swagelok vs Crestflo and Parker A-Lok vs Crestflo for comparisons with the others, or the master interchange overview for a broader view. For a focused look at second-source options, see Ham-Let alternative & second-source options.
Why Choose Crestflo Over a Standard Ham-Let Reorder
F1387-qualified dimensional interchange with major twin-ferrule systems gives an objective, published basis for a Ham-Let / Let-Lok drop-in.
- Ready stock for standard items · made-to-order for specials · 6-8 week delivery, with small MOQ.
- 316/316L through Hastelloy, Inconel, Monel, Duplex and Titanium Gr 2, in both imperial and metric.
- Heat-number traceability with MTC 3.1/3.2, certified to ISO 9001/14001/45001 and PED, with NACE MR0175/ISO 15156 available where the job calls for it.
- Private-label and made-to-print work out of the instrumentation division of an export house recognized by the Government of India, with four decades behind it. We Engineer Confidence.
Send Crestflo your Ham-Let / Let-Lok part numbers, and we'll return a dimensional-equivalent quote. Start here: Request a Quote. Curious about private labeling? Review our private-label program. For questions, contact sales@crestflousa.com or call +1 346 594 9005 (Houston, TX).
Ham-Let vs Crestflo FAQ
Is Crestflo interchangeable with Ham-Let / Let-Lok fittings?
Crestflo twin-ferrule fittings are built to match dimensions and have been performance-qualified to ASTM F1387. They aren't genuine Ham-Let parts, and we don't sell them as compatible with, or meant for mixing into, assembled Ham-Let components. Send us your part numbers, and we'll get you a dimensional-equivalent quote.
Is Let-Lok interchangeable with Swagelok?
Interchange between any two twin-ferrule brands comes down to dimensional fit and qualification, not brand compatibility. ASTM F1387 is the objective basis for that. Crestflo qualifies its own fittings to F1387; it doesn't claim compatibility with any brand's genuine components.
Is Crestflo affiliated with Ham-Let?
No. Crestflo makes dimensional-equivalent instrumentation fittings and valves, and it does so independently. Ham-Let® and Let-Lok® belong to the Ham-Let Group of companies as trademarks. Crestflo isn't endorsed by that group, nor is it a licensee.
Who makes Ham-Let and Let-Lok fittings?
Ham-Let® makes the instrumentation fittings and valves at issue here, including the Let-Lok® twin-ferrule tube fitting and the One-Lok® line. Both belong to the Ham-Let Group of companies. Corporate ownership can shift over time, though, so it's worth checking with the manufacturer directly for the current picture.
Which alloys can Crestflo supply as Ham-Let equivalents?
We work across the full stainless range: 316 and 316L, 304 and 304L, right up through 904L. Duplex 2205 and Super Duplex 2507 are on the list too, along with 254 SMO and AL-6XN. Add Alloy 20, the Inconel and Incoloy families, Monel, Hastelloy, and Titanium Gr 2. Imperial or metric, both are covered.
What is the lead time versus a Ham-Let order?
Crestflo keeps ready stock on hand for standard items and builds specials to order, with delivery running 6-8 weeks. Compare that to the major brands, where 20+ weeks is typical. Small minimum order quantities are available too. Crestflo doesn't quote competitors' lead times.
Do the fittings come with material certs and traceability?
Yes. Each part carries its own heat or lot number. EN 10204 MTC 3.1 comes as standard, and we'll issue 3.2 on request. Crestflo holds ISO 9001, 14001, and 45001 certification, along with PED.
Are Crestflo fittings NACE / sour-service capable?
Yes, where specified. Crestflo supplies materials to NACE MR0175 / ISO 15156 in alloys suited to sour-service applications.
Are these made in the USA?
No. Crestflo serves the US market, with manufacturing based in India. US and European melt is available on request, and full material traceability comes standard. The company built its supply chain for US drop-in, with delivery running 6-8 weeks. Details are on the origin and compliance page.
How do I get a Ham-Let-to-Crestflo cross-reference?
Send your Ham-Let / Let-Lok part numbers over via Request a Quote, or ask the engineering team for the cross-reference on the Ham-Let cross-reference page. Crestflo won't publish a part-number table it hasn't verified.
What are alternatives to major twin-ferrule brands?
Crestflo cross-references Ham-Let, Swagelok®, Parker®, Hy-Lok®, Hoke®, Fitok® and DK-Lok® by dimension, matching each to F1387 qualification standards. Check the master interchange overview if you'd like to compare brands side by side.
Related Cross-Reference & Product Pages
- All cross-reference & interchange guides
- Ham-Let / Let-Lok cross-reference
- Ham-Let alternative & second source
- ASTM F1387 interchange qualification
Get the fittings and valves lineup here: Twin-ferrule tube fittings, Needle valves, and Ball valves.
Material questions? Start with 316/316L instrumentation material, then work through the Single vs double ferrule comparison.
On the sourcing side, we've laid out Country of origin & TAA compliance in detail, and the Private-label program is covered separately.