For most buyers, the 304 vs 316 single ear clamp question has a short answer: buy 304. It is the grade single ear clamps are actually catalogued in, usually as 1.4301 or 1.4307. Only consider 316 (1.4401 or 1.4404) for salt-wetted, chloride-washed or pool-hall joints. Even then, expect a special order, and check that the maker publishes its own closing-force data for that grade.
That answer only helps if you can read the documents in front of you. On single ear clamp data sheets the grade usually hides in a seven-character material number rather than the word “304”. This guide reads a typical sheet line by line, then covers what crimping does to each grade, the closing tool, and a decision table by environment.
The one paragraph you need on the alloys themselves
Both grades are austenitic chromium-nickel stainless steels. 316 adds roughly 2 to 3 percent molybdenum, which raises its resistance to localised chloride attack such as pitting and crevice corrosion. That is the whole technical case for 316 on a hose joint. Mechanical properties and appearance are close, and price and availability are where they differ. For the full composition comparison, read our main article on 304 vs 316 stainless steel. The rest of this page deals only with what is specific to single ear clamps.
What single ear clamp catalogues actually offer
Before settling any 304 vs 316 single ear clamp question, check which grades the market really sells. We went through several makers’ published catalogues and distributor data pages in October 2026, looking at standard 1-ear clamps, stepless 1-ear clamps and pinch-style single ear clamps. The pattern was consistent: the stainless line is 304-family, the economy line is zinc-coated carbon steel, and 316 did not appear as a standard catalogue option for any single ear clamp we checked.
| Source checked | Single ear product | Material line as printed | 316 listed as standard? |
|---|---|---|---|
| Oetiker 1-Ear catalogue page | Product groups 153 and 154 | 1.4307 / UNS S30403; PG 154 adds a 1.4310 / S30100 insert | No |
| Oetiker StepLess data sheet | PG 167 (stainless), PG 117 (coated steel) | 167: 1.4301 / UNS S30400. 117: galvanised or zinc-plated steel band | No (sheet mentions unnamed “optional alternative materials”) |
| Mikalor brochure (via Bossard) | 1-ear clips, plain and inner-ring | W1: St 34 zinc-plated. W4: stainless A2 / AISI 304 | No (W5 appears in the general table, not on ear clip pages) |
| Dixon pinch single ear page | 123R and related sizes | 304 stainless, 1/4 in wide, 0.030 in thick | No |
| A UK distributor’s single ear range | Single ear stainless clips | DIN 1.4301 | No |
So the realistic choices on most single ear jobs are 304-type stainless, zinc-plated or galvanised carbon steel, or a special-order 316 batch if the volume and lead time justify it. Smaller resellers do list “316” single ear clips, but treat those listings with care. Ask for a mill certificate before you rely on the label, because a resold part number is not a material test.
Reading a single ear clamp spec sheet, line by line
The headings below follow the order in which the information usually appears on a 1-ear data sheet or order table. The examples come from the Oetiker 1-Ear and 2-Ear catalogue pages and the Oetiker 117/167 StepLess technical data sheet, because they are the most complete public examples. Other makers use different codes for the same information.
Line 1: the product group or series number
Ear clamp makers sort their range by product group, and the group number often tells you the material before any grade is printed. In Oetiker’s numbering, 167 is the stainless StepLess family and 117 is the coated-steel version of a similar design. Order numbers built on those prefixes (a part number starting 167… versus 117…) carry that distinction through to the invoice. Mikalor does the same with its W-class suffix, where W1 means zinc-plated steel and W4 means stainless. If you are cross-referencing an old part number, decode this line first. A buyer who swaps a 117-series clamp for a 167 has moved from coated carbon steel to stainless without the drawing ever saying “304”.
What this line will rarely do is offer a 316 variant under its own number. If a catalogue lists a family in only one stainless grade, a 316 version is an engineering enquiry, not an order-table pick.
Line 2: the material number
European sheets give the EN material number (from EN 10088). North American sheets give the UNS number. Some give both. The codes you are likely to meet on a single ear clamp are:
- 1.4301 / UNS S30400: standard 304. The most common stainless ear clamp grade.
- 1.4307 / UNS S30403: 304L, the low-carbon version. Oetiker prints this for its 153 and 154 1-ear groups. For a clamp that is never welded, the corrosion behaviour in service is essentially that of 304.
- 1.4310 / UNS S30100: 301-type spring stainless. On the PG 154 sheet it is the insert (the bridge under the ear that closes the gap), not the band. It is chosen for strength, not for extra corrosion resistance.
- 1.4401 / UNS S31600 and 1.4404 / UNS S31603: 316 and 316L. These are the codes to look for if a supplier says the clamp is 316. If the sheet or certificate shows 1.4301 or 1.4307, the clamp is 304-type, whatever the sales listing says.
- 1.0338, DC04, SAE 1008/1010, St 34: low-carbon steels used for zinc-plated or galvanised ear clamps. These are not stainless at all.
The same alloy simply carries several names across the EN, UNS and AISI systems. The practical rule is simple: the material number on the certificate decides the grade, not the word “marine” or “316” in a product title.
Line 3: the finish or surface condition
For coated-steel ear clamps, this line reads “zinc-plated”, “galvanised” or sometimes “Galfan” (a zinc-aluminium coating). For stainless clamps it is often blank or reads “degreased”, which is a cleanliness condition for assembly lines and medical or fluid-handling users. It is not a corrosion upgrade. A degreased 304 clamp is still 304.
This line shows the real alternative to 304 on cost-driven jobs. On a dry appliance hose, the choice is usually zinc-plated steel versus 304, not 304 versus 316. Once the clamp sees condensation, road splash or washdown, the coating is consumed and the steel rusts. The step up to 304 is the big one; 304 to 316 is a smaller, targeted upgrade.
Line 4: band width × thickness
Single ear sheets give the band cross-section as width × thickness in millimetres. The 167 StepLess sheet, for example, lists 5.0 × 0.5 mm for the smallest diameters, 7.0 × 0.6 mm and 9.0 × 0.6 mm through the main range, and 10.0 × 0.8 mm or 10.0 × 1.0 mm for heavy-duty versions. Imperial pinch-clamp listings give the same information differently, for example 1/4 in wide by 0.030 in thick.
Thickness is relevant to grade selection for a reason that is easy to miss: a thin band has less metal to lose. A shallow pit that would be cosmetic on a 1.0 mm band can go a long way through a 0.5 mm band. If a small-diameter clamp in a 0.5 mm band sits in a salty or chlorinated environment, it is a stronger candidate for 316 than a heavy 1.0 mm band in the same place.
Line 5: ear width
Ear width (often shown as “s” on dimensioned drawings) is the width of the ear before closing. It sets how much circumference the clamp can take up when crimped. On the 167 sheet it runs from about 4 mm on the smallest 5 mm bands to 10 mm on the larger 7, 9 and 10 mm bands. Ear width is a sizing parameter, and our guide on how to choose a single ear clamp covers how to use it. For the grade question, the point is that a wider ear means more metal is bent at the crimp, and more cold-worked metal means more locked-in stress. The crimp section below explains why that matters.
Line 6: maximum closing force and recommended tool
This is the line installers care about most. Oetiker’s 1-ear table, for instance, gives maximum closing forces for stainless PG 153 clamps of 1,400 N, 2,300 N and 2,800 N across three diameter bands. PG 154 is rated a little higher, up to 3,600 N on the largest sizes. Each force band is matched to a manual pincer, a pneumatic tool or a cordless tool. The StepLess sheet goes further and gives a closing force per band cross-section, from about 1,000 N on the 5.0 × 0.5 mm band to several thousand newtons on the heavy-duty bands.
Note what this line is tied to: a specific band size in a specific material. The figures on these sheets are published for the 304-type material the sheet lists. They are not general numbers for “an ear clamp of this width”. We come back to this under the closing-tool section.
Line 7: the corrosion rating
Some sheets print a neutral salt-spray result to DIN EN ISO 9227. The 117/167 StepLess sheet quotes at least 96 hours for zinc-plated steel, at least 144 hours for Galfan-coated steel and at least 1,000 hours for the 1.4301 stainless version. These are the maker’s published minimums. They are useful for comparing coated steel with stainless, which is the comparison they were written for.
They are much less useful for 304 vs 316. A salt-spray cabinet is a controlled fog test, not a pool hall, a road in winter or a chlorinated cleaning cycle. No sheet we checked publishes a 316 single ear figure to compare against, and you should not assume a multiple. Ask the supplier for test evidence in conditions close to yours, or rely on the environment table later in this article.
| Spec sheet line | Example of what you’ll see | What it tells you about 304 vs 316 |
|---|---|---|
| Product group / series | 153, 154, 167, 117; W1, W4 | Often fixes the material family before any grade is printed |
| Material number | 1.4301, 1.4307, 1.4310 insert, 1.0338 | The deciding line. 316 would show as 1.4401 or 1.4404 |
| Finish | Zinc-plated, galvanised, Galfan, degreased | Shows the cheaper alternative to 304; “degreased” is not a grade |
| Band width × thickness | 5.0 × 0.5, 7.0 × 0.6, 10 × 1.0 mm | Thinner bands have less corrosion allowance, so they gain more from 316 |
| Ear width | 4 to 10 mm | Wider ear means more cold-worked metal at the crimp |
| Max closing force + tool | 1,400 to 3,600 N on 1-ear sizes | Published for the listed grade; a 316 batch needs its own figure |
| Salt spray (ISO 9227) | 96 h, 144 h, ≥1,000 h | Compares coatings with stainless; says nothing about 316 |
What the crimp does to 304 and 316
Closing a single ear clamp is permanent plastic deformation: the ear, already cold-formed at the factory, is squeezed shut on site and that bent metal holds the joint. Three consequences matter for the grade choice.
Residual tensile stress lives in the ear
The closed ear and the band next to it carry locked-in stress, and the whole band is under hoop tension from the clamping load. Stress alone is harmless to stainless. Combined with a chloride film and the right temperature, though, it is one of the three conditions for chloride stress corrosion cracking. The UK Health and Safety Executive’s guidance on stainless steel in swimming pool buildings names hose clips among the heavily cold-worked items most vulnerable to that cracking. It also says plainly that both 304 and 316 are susceptible. Upgrading to 316 does not remove this risk. In a warm, chloride-laden indoor atmosphere, a single ear clamp in either grade should be treated as an inspection item, and safety-critical joints may need a more resistant alloy or a different fastening method altogether.
Cold work can make the ear slightly magnetic
Buyers sometimes test a crimped clamp with a magnet, find that the ear attracts it, and conclude they were sold the wrong steel. Usually they weren’t. Heavy cold deformation can turn part of an austenitic structure into martensite, which is magnetic. Australia’s stainless association notes in its guidance on magnetic effects in stainless steels that the effect is weaker in alloys richer in austenite stabilisers such as nickel. 316 carries more nickel than 304, so a crimped 316 ear generally picks up less magnetism than a crimped 304 one. That is one reason a magnet is a poor way to sort the two grades after installation. Our article on magnetic vs non-magnetic stainless steel explains the effect in more depth.
The ear creates crevices
A closed ear has two legs pressed close together, with a narrow gap between them. The band also sits tight against the hose, and on 154-style designs an insert sits under the ear. Each of these is a crevice where moisture and salt can collect and dry out slowly, and crevice corrosion is exactly the chloride attack that molybdenum helps 316 resist. On a clamp that gets wet with salt water and then dries, the crevice at the ear is where you would expect 304 to stain first. How much that matters depends on band thickness (Line 4).
The takeaway is that 316 helps against crevice and pitting attack at the ear. It does not make a crimped ear immune to stress corrosion cracking in hot or concentrated chloride conditions, where both grades share the same weakness.
The closing tool and ear clamp closing force by grade
Single ear clamps are closed with pincers or with pneumatic or cordless tools. Changing the grade does not change the tool: the jaws, the ear geometry they are built to fit and the closing method are the same whether the band is 304 or 316. What controls the joint is the closing force, and for a production line that figure comes straight from the data sheet line discussed above.
The catch is that the published closing forces we found are all for the 304-type grade printed on the sheet. We could not find a maker’s published closing-force table for a 316 single ear clamp, and we will not guess whether 316 or 316L needs more or less force for the same band size. If you order a 316 batch:
- Ask the supplier for the recommended closing force for that grade and band cross-section in writing, rather than reusing the 304 figure.
- If you use force-controlled pneumatic or electronic tools, run first-article checks on the 316 parts (ear gap after closing, pull-off and leak checks on your hose and fitting) before you change the setting for the whole line.
- Keep 304 and 316 stock physically separate. After crimping, the two look identical, and as noted above a magnet will not reliably tell them apart.
- For manual pincers, which do not measure force, check the closed ear against the supplier’s gap specification on a sample from each new batch.
Over-closing overstresses the band beside the ear, the part already carrying the most residual stress. A correctly closed 304 clamp can outlast an over-crimped 316 one, so the tool setting deserves as much attention as the grade.
304 vs 316 single ear clamp: decision table by environment
The table pairs common single ear applications with a recommended starting grade. It assumes a correctly sized and correctly closed clamp. Where we recommend 316, the realistic route is a special order with a mill certificate, because, as the catalogue survey shows, 316 single ear clamps are rarely a stock line.
| Environment | Starting grade | Why | Watch for |
|---|---|---|---|
| Indoor appliance (washing machine, dishwasher, coffee machine, dry cabinet) | 304, or zinc-plated steel if fully dry | Fresh water and mild detergents; 304 has plenty of margin | Coated steel near drain lines or condensation will rust |
| Automotive underbody (CV boots, fuel and vacuum lines, washer lines) | 304 | The standard grade for ear clamps in this service; road salt exposure is intermittent and gets rinsed off | Thin 5 mm bands in coastal or heavily salted regions: inspect, or consider 316 for long-life fleet work |
| Potable water and PEX-type crimp joints | 304 (as supplied to the relevant fitting standard) | Clamp systems for PEX are made to fitting-system standards such as ASTM F2098; the catalogue clamps we saw were 304-type | Follow the fitting system’s own clamp and tool requirements rather than swapping grades |
| Pool and spa equipment (pump, heater and filter hoses) | 316 for wetted outdoor equipment; review indoor plant-room joints case by case | Chlorinated splash and drying cycles favour molybdenum for pitting and crevice resistance | Warm indoor pool atmospheres can crack both grades; inspect and do not rely on 316 alone |
| Coastal (salt spray, boat tenders, dock equipment, seaside HVAC) | 316 where available | Salt deposits sit in the ear crevice and are not rinsed by rain in sheltered spots | Rinse access and inspection matter as much as grade; check band thickness |
| Food plant washdown (chlorinated or acidic sanitisers) | 304 for mild, rinsed cycles; 316 for chlorinated sanitisers and hot washdown | Chloride-based sanitisers and residue in the crevice favour 316 | Confirm that sanitiser concentrations and temperatures sit within the hose and clamp maker’s guidance |
Two rows need extra comment. On PEX-type potable water joints, the clamp is part of a tested fitting system. The published scope of ASTM F2098 covers stainless steel clamps used with PEX and PE-RT insert fittings, and the clamp has to meet the material requirements in that standard. Swapping in a different maker’s clamp, in any grade, because it “looks the same” can take the joint outside its listing. In pool and spa work, the honest position is that 316 is the better grade for wetted outdoor equipment, but it is not a cure for indoor pool atmospheres. A Nickel Institute paper on pool-hall cracking recorded failures in both grades.
When a 316 single ear clamp special order makes sense
Because 316 is rarely stocked for this clamp type, a special run is worth the effort when most of these are true:
- The joint will see salt water, chlorinated water or chloride sanitisers repeatedly, and will dry out between exposures.
- The clamp is hard to reach or expensive to replace, so service life matters more than unit price.
- Your volume justifies a dedicated run and your schedule can absorb the longer lead time (ask about minimum quantities early).
- You can get the closing-force data, a mill certificate showing 1.4401 or 1.4404, and lot traceability, so the grade can be proven later.
Otherwise, a correctly closed 304 clamp with a planned inspection interval is usually the better buy in the 304 vs 316 single ear clamp decision.
Stepless designs such as the 167 family raise their own grade questions, covered in 304 vs 316 stepless ear clamps. If your joint uses two ears, our 304 vs 316 double ear clamps article works through three real case files. For a plain-language introduction to the clamp itself, see what is a single ear clamp.
OneTouch Exim and single ear clamps: what we can and cannot supply
To be direct: OneTouch Exim does not stock single ear clamps in any grade. Our clamp range is built around worm gear, constant torque, T-bolt, V-band, lined and high-torque clamps for heavy-duty and industrial users.
What we can do is this. If your drawing allows an adjustable clamp instead of a crimped one, small hoses that normally take a single ear clamp can often take a mini worm gear clamp. Our all-stainless minis are the closest match in size:
- 4SS0004 mini clamp: about 0.22 to 0.63 in, 5/16 in band, 1/4 in hex, 45 in-lb rating, with a 301 stainless band and housing and a 410 stainless screw.
- 4SS0006 mini clamp: about 0.44 to 0.78 in, with the same band, hex, rating and materials.
- 4SC004M mini hose clamp: the standard-series option at 0.25 to 0.63 in, for dry, cost-driven uses.
These are not 316 and not a corrosion upgrade over a 304 ear clamp; our standard 4SC series is labelled not for marine service. Their advantage is different: they can be removed, re-tightened and fitted without a crimping tool. If you are weighing grades for these, our article on 304 vs 316 mini hose clamps covers them. You can browse the full range in our perforated worm gear clamps category, and check diameters against our hose clamp size chart.
If you must stay with a single ear clamp, send us the part number or the data sheet lines described above. We will tell you honestly whether we can source a match, or whether you are better served by going direct to an ear clamp specialist.
Single ear clamp grade questions buyers ask
In the 304 vs 316 single ear clamp choice, which is normal?
Normally 304-type. Every maker catalogue and data page we checked printed 1.4301 or 1.4307 (304 or 304L) for stainless single ear clamps, with zinc-plated or galvanised steel as the economy line. 316 is generally a special-order item for this clamp type.
My spec sheet says 1.4307. Is that worse than 1.4301?
No. 1.4307 is 304L, the low-carbon version of 304. Low carbon mainly matters for welded parts. For a crimped clamp in service, treat 1.4301 and 1.4307 as the same corrosion class. Neither one is 316.
Can I tell a 316 single ear clamp from a 304 one with a magnet?
Not reliably. Both are essentially non-magnetic as annealed strip, and both can become slightly magnetic where the ear has been cold-formed and crimped. 304 tends to show the effect more, but the difference is not a sorting method. Use the mill certificate and lot labelling, or a proper alloy analysis if you need proof.
Do I need a different pincer for 316 ear clamps?
The tool type is the same. What you need is the supplier’s recommended closing force for the 316 band size you are buying, because published force tables are written for the grade printed on the sheet. Check closed-ear results on samples before changing a production setting.
Is a zinc-plated ear clamp good enough instead of 304?
Inside a dry appliance or cabinet, often yes. Anywhere with condensation, splash, road salt or washdown, no: the coating is gradually used up and the steel then rusts. In maker salt-spray ratings, coated ear clamps are rated in the low hundreds of hours, while the stainless versions are rated at 1,000 hours or more.
Will 316 stop my ear clamps cracking in a pool plant room?
Not on its own. Published guidance on indoor pool atmospheres reports stress corrosion cracking in both 304 and 316, with heavily cold-worked items such as hose clips among the most vulnerable. Use 316 for better pitting resistance, but also inspect regularly, keep surfaces washed and consider other materials or clamp types for critical joints.
Send us the sheet, we’ll read it with you
If you have a single ear clamp part number, an old drawing or a data sheet you are unsure about, look it up first in our clamp cross-reference to see whether one of our clamp families can take over the joint. If it can’t, or you want a second opinion on grade, band size or a mini worm gear replacement, send the details through our contact and quote page. We will reply with what we can supply and what we can’t.