A quotation for a “35 mm² M8 cable lug” identifies a conductor-size reference and a mounting reference. It does not define the complete part. The palm may be too wide for the terminal, the barrel may obstruct the hardware, or the lug may lack documented compatibility with the chosen conductor construction.
Compare the dimensional drawing and cable compatibility together. This guide focuses on the lug between the cable and the mounting surface. The separate battery terminal fit guide covers the wider battery interface and connection stack.
Name the drawing features before requesting dimensions
The barrel receives the stripped conductor. The palm, also called the tongue, is the flattened mounting portion. Its eye or stud hole locates the lug on the mounting hardware. A transition joins the palm to the barrel; an angled lug adds orientation and height requirements.
Request the manufacturer, complete part number, drawing number and revision. Mark the required dimensions on that drawing. Letters such as A, B or L have meaning only within the associated drawing; do not combine dimensions from unrelated diagrams because their symbols look similar.
TE Connectivity's page for SIMEL 708473-2 separates an M8 stud description, barrel inside diameter, barrel length, lug width and palm-hole diameter. It also directs design users to the product drawing. Its listed barrel inside diameter is 7.9 mm and lug width is 17 mm. These values illustrate separate geometry fields for that named product, not a recommended battery-lug size or a tolerance specification. TE 708473-2 product dimensions.
Check whether a dimension is a controlled limit, a nominal catalogue value or a reference dimension. If the needed acceptance tolerance is missing, leave the requirement unresolved until the supplier supplies an applicable drawing or an agreed specification.
Separate the nominal stud from the actual lug hole
For a lug with an unthreaded eye, the mating stud designation and the eye's manufactured diameter describe different features. Request the nominal stud, actual hole dimension and tolerance, hole count, and relevant centre positions independently.
Panduit's LCA6-14F-L customer drawing identifies a 1/4-inch stud size alongside a separately dimensioned hole. It also identifies the part as a one-hole, standard-barrel lug with a 90° tongue. This demonstrates why a short stud-size description should not replace a dimensioned drawing. Panduit LCA6-14F-L customer drawing.
Do not silently substitute an inch stud for a nearby metric designation. Have the responsible designer confirm the actual mating hardware, eye limits and locating conditions. Similarly, a slotted palm or two-hole pattern requires its own width, length, orientation and centre-spacing review.
Record the hole centre relative to an identified palm edge or other defined reference. Total lug length alone does not establish where the hole sits relative to the barrel, cover or neighbouring terminal.
Check the whole palm and the cable exit
The palm's outside width, flat contact length, thickness and edge shape affect different parts of the fit review. Identify the intended seating surface and the surrounding space. Check the allowed dimensional extremes, rather than comparing only nominal widths.
Request the distance between the hole centre and the barrel transition, plus the barrel's outside diameter and usable length. Review whether the proposed geometry leaves the required hardware access and cover clearance in the assembled position. A lug can have the requested hole size while its transition occupies space reserved for another component.
For angled lugs, identify the viewing direction, bend orientation, angle and height from the seating plane. Include the finished cable route, boot or sleeve where applicable. Avoid approving a loose lug's envelope and assuming the terminated cable will occupy the same space.
The following three-column table is an RFQ template. It contains no universal tolerances or installation clearances.
On small screens, swipe or scroll sideways to read every column. Keyboard users can focus the table and use the arrow keys.
| Feature | Information to specify | Evidence needed for comparison |
|---|---|---|
| Mounting eye | Stud reference, actual bore limits, hole count and centres | Matching dimensional drawing with units and tolerances |
| Palm | Width, flat length, thickness and relevant edge profile | Maximum/minimum envelope and seating review |
| Hole-to-barrel relationship | Defined measuring references and required distance | Dimensioned transition and hardware-access view |
| Barrel | Inside/outside dimensions, usable insertion length and entry form | Lug drawing plus exact conductor compatibility |
| Orientation | Straight/angled form, viewing direction and seating plane | Side and end views or controlled model |
| Finished termination | Cable exit, protective parts and required surrounding space | Identified assembly drawing or dimensional fit record |
Treat barrel fit as a documented combination
Cable cross-section is not the same quantity as the outside diameter of the stripped conductor bundle. The RFQ should identify the cable manufacturer and part, conductor size, material, strand construction and the applicable conductor-class designation.
Klauke describes its F-series copper tubular lugs specifically for fine and superfine stranded round conductors, including EN 60228 Classes 5 and 6, with pipe dimensions adapted to those constructions. This is family-specific compatibility information, not approval of every lug bearing the same nominal cross-section. Klauke F-series conductor compatibility.
Panduit's cited LCA6-14F-L drawing instead identifies 6 AWG stranded copper and particular Class B and Class C constructions. Keep those stated systems and constructions intact in the comparison; do not translate a generic “flexible cable” description into a documented match.
Ask for the lug manufacturer's applicable cable and processing instructions. A sample conductor that can be pushed into a barrel establishes only that observation. It does not establish the approved crimp combination or connection performance. Refer to the lug crimp tooling and evidence guide for those separate process checks.
Compare a fictional dimensional proposal
Consider two hypothetical straight lugs for a fictional 35 mm² Class 5 cable project. The design authority has set an 18.0 mm maximum palm width, an eye diameter range of 8.4–8.8 mm, and a minimum distance H of 14.0 mm. H is defined on the project sketch from the hole centre to the start of the straight cylindrical barrel, measured along the cable axis.
These invented values demonstrate a comparison method. They are not M8 standard dimensions, recommended clearances or real supplier specifications.
Offer A states palm width 17.8 ± 0.3 mm, eye diameter 8.6 ± 0.2 mm and H of 14.2 ± 0.4 mm. Its nominal width and H appear acceptable, but the permitted width reaches 18.1 mm and H can fall to 13.8 mm. The eye range matches the fictional requirement; the other two ranges do not. One favourable dimension cannot clear the proposal.
Offer B states width 17.5 ± 0.2 mm, eye diameter 8.6 ± 0.1 mm and H of 14.5 ± 0.2 mm. Its resulting ranges fit these three specified limits. However, its documentation says only “35 mm² copper” and does not establish coverage of the required Class 5 construction.
For A, request a conforming alternative or a formal design review of the deviations. For B, close the conductor-compatibility gap and the remaining drawing requirements before release. Do not describe B as fully approved merely because its three dimensional ranges pass.
If suppliers measure H from different locations, first reconcile their references. Arithmetic on unlike dimensions produces a misleading comparison even when all values are expressed in millimetres.
Close dimensional gaps before sample approval
Agree which dimensions will be measured, the sample condition, measurement references and acceptance limits. Distinguish a loose-component inspection from an inspection of the finished crimped and protected assembly. Record the part, cable, drawing revision and sample identity with actual readings.
A fit check should use the approved mating parts or a suitable dimensional fixture. It does not establish current capacity, temperature rise or endurance. Keep those separate evidence requirements connected to the same identified assembly.
Carry accepted deviations and dimensional revisions into the first-article and change-control record. A change to palm geometry, barrel construction, conductor or protective parts may reopen the fit review.
Send the cable specification, lug and mating drawings, dimensional limits, proposed quantities and required sample records together. Ask suppliers to identify tooling, special geometry and documentation costs separately, with current commercial terms for that configuration.
Buyer FAQ
Is an M8 lug description enough to confirm the hole diameter?
No. Request the actual hole dimension and tolerance, together with the mating stud and drawing. The nominal mounting reference does not describe every manufactured feature.
Can equal cross-sections guarantee the same barrel fit?
No. Verify the exact conductor construction against the lug manufacturer's applicable instructions. Matching nominal area and apparent insertion are not complete compatibility evidence.
Can we drill a larger eye or bend the palm to make a sample fit?
Treat either action as a proposed part change. Obtain the necessary manufacturer and design-authority review; original drawing and qualification evidence should not be assumed to cover a modified lug.
What should a comparable quotation include?
An identified lug and cable combination, controlled dimensional drawing, explicit deviations, sample inspection scope and the commercial terms for those requirements. Keep missing evidence visible until it is resolved.