How Snatch Block Ratings Are Published: WLL, MBS, or Neither

Read the exact word printed next to a snatch block’s headline number before you trust it. “Working Load Limit” and “Minimum Breaking Strength” are not the same number and are sometimes 2x apart on the identical physical block, and a growing share of the market publishes neither term at all. Below is what WARN, Factor 55, ARB, Smittybilt, Rhino USA, GearAmerica, Van Beest, Superwinch, Bubba Rope, and Yankum each actually print, plus what to do when a manufacturer hasn’t told you which basis its number uses.

WARN, Factor 55, ARB, Smittybilt, Rhino USA, GearAmerica, Van Beest / Green Pin, Superwinch, Yankum, and Bubba Rope are trademarks of their respective owners; RiggingOps is not affiliated with or endorsed by any of them.

Follow your specific block or ring’s own manufacturer instructions first. Where a product’s own manual or spec sheet differs from anything summarized below, the manufacturer’s own page wins. This page catalogs what is published, not what any block should be rated. For the underlying definitions of Working Load Limit and Minimum Breaking Strength, and how safety factor connects them across recovery gear generally, see WLL vs. MBS; this page stays specifically on how block and ring manufacturers publish, or fail to publish, that basis.

Scope: This Page Is About Publishing Basis, Not Sizing

This page does not re-explain what WLL and MBS mean in general, that ground is covered on WLL vs. MBS. It does not repeat the full angle-load physics of a double-line pull, covered on how to use a snatch block and how much force a winch redirect puts on the anchor. And it doesn’t re-run the full buying-guide comparison already published on best snatch blocks, which carries current picks with full spec tables and Amazon links.

What follows is narrower: a per-product table of exactly what each manufacturer’s own page says about the basis of its headline number, sourced line by line, with the products whose basis genuinely cannot be determined given their own section instead of a guess.

What ASME B30.26 and BS 7901 Actually Require of a Block

Two named standards show up repeatedly on the product pages below, and it matters what each one actually requires, not just its name.

ASME B30.26 covers rigging hardware, including snatch blocks by name. A secondary engineering source (Holloway Houston Lifting) summarizes the requirement directly: “Blocks must be permanently marked with the manufacturer’s identification, Working Load Limit, and approved rope size range.” That’s a marking requirement, confirmed as live, readable text on that source’s page; it doesn’t by itself fix a single universal design factor for every block category the way it does for shackles (5:1, covered on our WLL vs. MBS page). WARN’s own product pages state its blocks carry a 4:1 design factor under this standard.

BS 7901 is a British Standard covering vehicle recovery equipment specifically, and it’s paywalled. The BSI Knowledge page that indexes it exposes only metadata (title, publication status, keyword descriptors); it does not expose the standard’s own scope or design-factor text as readable content. The “2:1 design factor for vehicle recovery” figure that shows up below comes from WARN’s own product pages repeating that characterization, not from this page’s own reading of BS 7901’s text, which sat behind that paywall. Treat the 2:1 figure as WARN’s stated characterization of the standard, not a quotation this page verified against the standard itself.

Products That Publish Both a WLL and an MBS: The Design Factor Is Visible

These products give you the full picture: a working load figure, a breaking strength figure, and (dividing one by the other) the design factor connecting them. Where a manufacturer states its own ratio directly, that’s labeled below as the manufacturer’s own figure. Where this page divided the two published numbers itself, that division is labeled as this page’s own calculation, since a manufacturer’s rounded WLL and MBS numbers don’t always divide out to a perfectly clean ratio.

The most directly useful row in this table is WARN’s 15640. It’s the one product across this entire research where the identical physical block carries a manufacturer-stated 4:1 figure under one named standard and a manufacturer-stated 2:1 figure under a second named standard, on the same page, in the same breath. Nothing else checked for this page discloses two named standards on one SKU; Factor 55 states two safety factors but doesn’t attribute either one to ASME or BS 7901 by name, which makes it a dual-factor disclosure, not a dual-standard one.

ARB’s Ultra Light Snatch Block (10100020A) is a partial version of this same picture. Its own product page lists “Maximum Load: 19845lbs” and, separately, “Breaking Strength: 38580lbs,” two genuinely distinct figures. Dividing them gives 1.94:1, close to the 2:1 BS 7901 convention seen elsewhere in this table, but ARB’s page does not use the words “WLL,” “MBS,” or “BS 7901” anywhere, and does not attribute that ratio to any named standard. Treat the 1.94:1 figure as this page’s own division of two unlabeled ARB numbers, not a standard ARB claims to follow. Worth flagging separately: ARB’s own product title rounds the 19,845-lb Maximum Load figure up to “20,000lb,” a real, if minor, gap between the marketing headline and the number on ARB’s own spec sheet.

A contrast case worth naming, not folding into the ratio table above: Van Beest’s Green Pin Snatch Block S line, sold across a 2- to 125-ton range, doesn’t publish a single WLL/MBS pair per size the way the vehicle-recovery brands above do. Instead its own product page states the relationship as a fixed formula: “MBL equals 4 x WLL,” a manufacturer-stated 4:1 design factor built into the product line by design, not derived from two separately published numbers. Green Pin’s page carries CE and lifting-equipment certification marks but no BS 7901 vehicle-recovery figure alongside the ASME/EN-adjacent industrial rating. It’s useful here as a contrast, not a pick: this is what a single-standard industrial rigging block looks like, built to one fixed ratio with no second, vehicle-recovery-specific number layered on top the way WARN’s SKUs carry both.

Products Where the Rating Basis Cannot Be Determined From Published Text

These products publish a number. None of them publish enough surrounding language to tell you, from the manufacturer’s own page, whether that number is a safe working figure, a failure figure, or something else. This page is not guessing at a basis for any of them.

ARB’s ARB2091A is the clearest example in this set. It carries no rating vocabulary of any kind on ARB’s own storefront, not even an unlabeled WLL-versus-MBS ambiguity, for a number that appears exclusively in the product’s name. That’s a more useful example of the labeling gap than a mislabeled WLL claim would be, and it corrects a claim published elsewhere on this site: our how to use a snatch block page previously described this exact model as “rated 15,000 lb WLL.” A fresh check of ARB’s own product page found no WLL language supporting that; the page has been corrected to describe ARB2091A accurately, and this page is the sourced reference for that correction.

Products That Publish Only One Half of the Ratio

A third category sits between the two above: products that do use real rating vocabulary, WLL or MBS by name, but publish only one side of the pair, so no design factor can be calculated at all.

Factor 55’s RRP and Bubba Rope’s ring both give you a safe-use number with no way to check the margin behind it. Yankum’s ring gives you the opposite: a tested failure point with no safe-use number at all, and “pull-apart tested” describes a real destructive test Yankum states it ran, which is a stronger claim than a bare, untested-sounding “breaking strength” figure, but it’s still a measured failure point, not a working load. None of these three gaps can be filled by guessing; each ring publishes exactly one half of the WLL/MBS pair.

Where a Listing’s Own Words Don’t Match Its Own Headline

Two small, real discrepancies surfaced during this research, worth naming rather than smoothing over.

GearAmerica’s Smart Snatch Block for ATV/UTV uses “MBC” in its own product URL slug (smart-snatch-block-for-atv-and-utv-24-000-lbs-12t-mbc-12-000-lbs-6t-wll), which could read as a third rating term distinct from MBS. The actual rendered text on that same product page states “24,000 LBS (12t) MBS & 12,000 LBS (6T) WLL,” using the standard MBS term, not MBC. This page reports MBS, the wording a reader actually sees on the page, and treats the URL slug’s “MBC” as a naming inconsistency in GearAmerica’s own URL, not a real third rating category.

ARB’s Ultra Light Snatch Block product title reads “20,000lb,” but the same page’s own spec table lists “Maximum Load: 19845lbs,” a number ARB’s own headline rounds up by about 1 percent. Not a safety-relevant gap on its own, but a real mismatch between ARB’s marketing title and ARB’s own spec sheet, on the same page.

How to Tell Which Basis an Unlabeled Number Is, and What to Do When You Can’t

1. Read the exact word next to the number, not just the number. “Working Load Limit” or “WLL” is a safe-use figure. “Minimum Breaking Strength,” “MBS,” or “breaking strength” is a failure figure. Neither of those words appearing anywhere on the page means the manufacturer hasn’t told you.
2. Check whether a second figure exists elsewhere on the same page. A single number with no counterpart, like Yankum’s MBS-only ring or Factor 55’s WLL-only RRP, doesn’t let you calculate a design factor even if the one figure you have is clearly labeled.
3. If a named standard is cited (ASME B30.26, BS 7901), check whether the manufacturer states the standard’s design factor directly, the way WARN does (4:1 and 2:1, stated on WARN’s own pages), rather than assuming a factor from the standard’s name alone.
4. If the page uses “capacity,” “rated at,” or “rating” with no WLL or MBS language anywhere else on the page, treat the number as unrated for sizing purposes. Smittybilt’s 2744, Superwinch’s 7750A, and WARN’s Epic 93195 all fall into this category. That’s not this page’s opinion of those products; it’s what those manufacturers’ own pages do and don’t say.
5. No manufacturer checked for this page publishes guidance for comparing its own numbers against a competitor’s. The closest thing to that guidance anywhere in this research is WARN’s own dual-basis disclosure on a single SKU, which teaches that two numbers on one block can differ 2x depending on standard, but stops short of telling you how to weigh its own WLL against, say, Smittybilt’s unlabeled capacity figure. That absence is real, not an oversight in this page’s research: it means the basis check above is something you have to do yourself, product by product, rather than something any brand will do for you.

Staying Consistent With the Snatch Block Calculator’s Own Logic

Our snatch block calculator already encodes the same conservative approach this page argues for. When a product carries more than one WLL-labeled figure, the way WARN’s 15640 and 63490 each do, the calculator uses the lower of the two published WLL numbers for sizing, on the reasoning that sizing against the higher figure could imply a block is safe under a standard the reader isn’t actually rigging to. And any product whose only published figure isn’t explicitly labeled WLL, Smittybilt’s 2744 and WARN’s Epic 93195 among them, is excluded from the calculator’s sizing comparison entirely, not by name, but because nothing on those products’ own pages matches a WLL label. This page’s tables above follow that same rule: a bare capacity figure is reported as exactly what it is, an unlabeled number, never treated as if it were a WLL for comparison purposes.

If you’re sizing a block or ring against your own winch’s line pull and rigging angle, run the numbers through the calculator directly rather than eyeballing the tables above against your winch’s rated capacity.

How We Sourced This

RiggingOps doesn’t test snatch blocks or recovery rings. Every figure on this page traces to a specific manufacturer’s own product page, read as live text and checked to confirm it returns as a normal web page, not a redirect to an image or a PDF. Where a manufacturer’s own page used ambiguous language (“capacity,” “rated at”) or a standard’s design factor couldn’t be verified against the standard’s own text (BS 7901’s paywalled scope), that’s stated plainly in the sections above instead of resolved by assuming the friendliest reading. Where this page performed its own division to derive a ratio a manufacturer didn’t state as a single number, that division is labeled as this page’s own calculation, not the manufacturer’s claim. Full sourcing and rating methodology: review methodology.

Related Reading

For the general definitions of WLL, MBS, and safety factor across all recovery gear, not just blocks, see WLL vs. MBS. For current snatch block and recovery ring picks with full manufacturer spec tables and buying guidance, see best snatch blocks. For the step-by-step of rigging a double-line pull, see how to use a snatch block. For the angle-load physics behind why a block and its anchor see close to double the winch’s line pull, see how much force a winch redirect puts on the anchor. This page is part of the broader recovery gear ratings pillar.