Lug and terminal RFQ checklist: what to send for a useful quote

A lug quote starts with the joint, not the part number

A request for a lug price often arrives as a part number and a quantity. That is enough for a catalogue item and not enough for a configured or custom lug. The supplier has to guess the conductor class, the stud, the palm angle, the plating and the test evidence. Each guess becomes either a price margin or a clarification email.

The checklist in this guide follows the order in which a lug is actually selected: conductor, interface, material, finish, proof. Send the answers in one document so that two suppliers are quoting the same joint rather than two different interpretations of it.

A quote built on missing data is not a lower price. It is a price with assumptions hidden inside it, and those assumptions surface at the first article or, worse, at installation.

Conductor: size, class and strip length

State the nominal cross-section and the conductor class. A 95 mm2 flexible cable and a 95 mm2 stranded cable need different barrel geometries even though the area is the same. The class tells the supplier whether the barrel must contain many fine strands or fewer coarse strands, and that changes the die.

Add the strand count if it is known, and the insulation strip length. A barrel that is longer than the strip leaves bare conductor outside the crimp. A barrel that is shorter cannot take the full conductor, and the missing strands become a hot spot.

• Nominal cross-section in mm2, not an approximate AWG equivalent
• Conductor class to IEC 60228, such as class 2, 5 or 6
• Strand count and strand material
• Insulation type and the strip length the tool will produce
• Whether the conductor is tinned, and whether the cable is aluminium

Interface: stud, spacing and angle

The palm is selected against the terminal, not against the cable. Give the stud size, the hole diameter, the hole spacing and the palm width. If the terminal has two studs, give the centre distance and say whether the lug is one-hole or two-hole. A two-hole lug holds orientation under vibration, but only if the spacing matches.

State the palm angle. A straight palm, a 45 degree palm and a 90 degree palm solve different space problems, and the angle changes the crimp access. A tool that cannot reach the barrel without loading the palm will produce a poor crimp even if the lug itself is correct.

Add the space around the joint, including clearance for the crimp tool and the bend radius of the cable. Panel builders often find that the lug is right and the tool cannot reach it, which turns a catalogue part into a rework item.

Material and finish: describe the environment

Name the base metal. Copper, brass and aluminium are not interchangeable, and a bimetallic lug is a separate decision rather than a material substitution. If the conductor is aluminium and the terminal is copper, say so at the top of the request and ask for the transition method.

Name the plating, the standard and the minimum thickness. Tin is the default for copper and brass. Silver suits high current or high temperature joints. Nickel is harder and more corrosion resistant but has higher contact resistance than either.

Describe the service environment in plain terms: indoor panel, outdoor sheltered, coastal, washdown, high temperature or vibration. That sentence decides more about the finish than a general note that the part must not corrode, and it gives the supplier a reason to recommend one coating over another.

Proof: die, pull test and documents

A crimp is a controlled deformation, so the quote should cover the die and the crimp height, not only the lug. If the buyer already has a tool, send the tool make and the die part number. If the supplier is expected to nominate a die, ask for the crimp height range and the pull test value that goes with it.

State the inspection level and the evidence. For a power joint, the usual pack is a crimp cross-section, a pull test at a stated sample size and a plating check. A visual check alone does not prove that the barrel is full or that the strands are undamaged.

Ask whether the price includes a sample crimp and a first article. A supplier who prices the lug but not the proof has quoted half the job, and the missing half appears as a separate charge after the order is placed.

The proof should use the cable the buyer will actually run. A sample crimp on a short bench length can hide a strip length problem or a strand that folds at the barrel entry. Ask for the sample to be made from the production cable and the production tool.

Volume, packing and delivery

Give the annual volume and the release size. A lug that is cheap at 100,000 pieces can be expensive at 500, because setup, testing and packing dominate a small order. The volume also decides whether a custom die is worth building or a standard barrel should be used.

State the delivery destination and the Incoterm. The same lug delivered DDP to a European warehouse and FCA at an Indian port are different landed costs, and the difference belongs in the comparison rather than in a later freight adjustment.

Add the packing requirement if the lug is plated or if the palm is easily damaged. Bulk bags, trays and labelled boxes change the handling cost and the risk of a rejected lot, especially when the parts are transferred between a crimp cell and a panel line.

If the part is supplied on a reel or in a kit, say so. A reel changes the packing, the label and the handling equipment, and a supplier who assumes a bag will quote a process that does not fit the line.

The fourteen item checklist

The table is the short version. Copy it into the RFQ and fill the right hand column, or send the drawing and mark the items that are already on it. A numbered reference is faster to review than a repeated description.

What to do when the design is not final

If the lug is still being chosen, send the cable, the terminal and the space, and say which parts are fixed. A supplier can then price a range and flag the option that carries the risk, which is more useful than a single number built on an assumption.

Ask for two prices: one for the preferred lug and one for the alternative that removes the tightest constraint. The comparison shows whether the constraint is worth designing out, and it gives the buyer a fallback if the first choice is unavailable.

Keep the RFQ and the answers with the drawing revision. When the cable or the terminal changes, the assumptions change with it, and a quote carried forward without them is a new guess with an old date.