A detachable connecting link lets compatible roller-chain ends be joined using a pin plate, a removable outer plate and a retainer. The spring-clip version shown here is distinct from a cast hook-type detachable chain. Its pins carry the chain-joint loads, while the clip retains the outer plate axially.
Detachable Chain Link Interactive Calculator
See a spring-clip roller-chain connecting link assemble from its pin plate, loose plate and retaining clip. Separately compare static tension in two equally loaded strands using entered strength and divisor assumptions. The result is a comparison threshold, not a manufacturer working-load rating.
Equation Used
- Two separate vertical chain strands carry the entered weight equally; this is not a duplex-chain capacity model.
- UTS percentage and both divisors are user assumptions, not verified data for a particular chain.
- Static force balance excludes chain self-weight, unequal sharing, acceleration, friction and external loads.
- The animation is an enlarged spring-clip connecting-link example; clip flex, tolerances and insertion force are not solved.
Ultimate tensile strength is a breaking-test value. Dividing it by entered factors alone does not establish a catalog working load, fatigue life or suitability for lifting. Use the chain and connecting-link manufacturer’s application ratings.
One connecting link, three visible parts
The enlarged animation starts with the two fixed pins already passing through the two inner-chain ends. The loose outer plate slides over both pins. The retaining clip then moves into the grooves near their ends, with its closed end facing the indicated chain travel.
The loop holds the assembled view, then shows unloaded removal in reverse order. Axial spacing and clearances are enlarged so the parts remain visible. The drawing does not solve the clip’s elastic snap, installation force or dimensional fit.
Different connecting links use different retainers or plate fits. This illustration does not represent a cast Ewart-style hook link, a riveted joining link or every roller-chain installation procedure.
Match the actual chain and connecting link
Connecting links are used in compatible transmission and conveyor chains to join their ends. The chain series, pitch, plate fit and retaining method must match the specified assembly. A removable plate is not automatically a hand-fit plate.
The load example below is a separate idealized support calculation with two vertical strands. It is not an endorsement of this pictured link for an elevator or suspended load.
Breaking strength is not a working-load rating
The calculator first multiplies entered chain ultimate tensile strength by the assumed connecting-link percentage. It then divides by the entered design and service divisors to form a comparison threshold C. The nominal static tension in each of two equally loaded strands is T = W/2.
The displayed percentage is 100T/C. It can exceed 100%; no value is hidden or capped. This arithmetic does not account for fatigue, dynamic loading or the actual manufacturer’s rating. The percentage assumption must not be mistaken for a universal connecting-link derating.
Example: two strands supporting 900 lbf
With entered chain UTS 6,100 lbf and an assumed link ratio of 80%, the assumed link breaking strength is 4,880 lbf. Divisors 8 and 1 give a comparison threshold of 610 lbf. Equal sharing of a 900-lbf weight gives 450 lbf per strand, or 73.8% of that threshold.
Changing the service divisor to 1.5 reduces the threshold to about 406.7 lbf and raises the ratio to about 110.7%. These are consequences of the entered assumptions. They do not predict failure timing or establish permissible chain speed.
Use application ratings rather than a universal rule
Manufacturer guidance distinguishes one-time tensile strength from allowable operating load. Connecting-link construction, plate fit and chain series can change the relevant rating. Speed, shock, lubrication and fatigue also require the applicable selection method.
No universal maximum speed, inspection interval or strength reduction is assigned here. The spring clip secures the outer plate; it is not drawn as the main tensile member between the chain ends.
Connecting-link questions
Which way does the clip face?
For the illustrated spring-clip construction, the closed end faces the chain’s direction of travel, consistent with the cited manufacturer instructions.
Why is the loose plate fitted before the clip?
The plate must be behind the pin grooves so the retainer can seat in those grooves and hold it axially.
Does the 610-lbf default result certify a working load?
No. It is an arithmetic threshold based on the entered strength percentage and divisors. Use the actual product and application ratings.
Do two strands always share the weight equally?
No. W/2 is the stated ideal assumption. Unequal geometry, stiffness or alignment can create unequal loads.
Is this the same as cast detachable chain?
No. The animation shows a spring-clip roller-chain connecting link. Cast hook links use a different construction.
References
Renold, Chain Technical Information, connecting-link parts, cover-plate installation and spring-clip orientation. ZEXUS Roller Chains catalog, technical information page 74, connecting-link variations, clip seating and the distinction between ultimate tensile strength and working load.
Building or designing a mechanism like this?
Explore the precision-engineered motion control hardware used by mechanical engineers, makers, and product designers.
