Branch Point Enquire

On the harness

Boots on cable harness assemblies

Three branches off one entry: GHS3-N-407 goes on over a 14mm and closes down to b 6.6mm.

The exit decides the part; the chart only decides the size

Two things are settled before a boot is chosen. The connector fixes the exit angle. The harness fixes how many cores leave that exit. Diameter comes third, and it is the only one of the three a selection chart can answer.

A harness boot does three jobs at the same point. It insulates the joint. It takes the pull off the termination and puts it into the jacket. It closes the assembly against water, fuel and dust. The two-outlet and three-outlet sheets state all three in one line, in that order.

Specifying against one of the three is where these parts go wrong. The bore pair answers insulation and grip and says nothing about lining. Lining settles the seal, and it settles what happens the second time anyone opens that loom.

GHS2-N and GHS3-N are published with or without adhesive lining, in semi-rigid flame-retarded polyolefin, standard colour black. That is one line on a purchase order and a permanent decision on the harness. A lined boot bonds to the jacket as it recovers. Taking it off takes the bond with it, so the next one goes onto a surface cleaned back to bare jacket first. An unlined boot leaves the jacket as it found it, which is worth more on a loom built to be repaired than on one built to be sealed.

Two further figures decide a vehicle or airframe fit before the fluids do. Oxygen index on the two-outlet and three-outlet sheets is at least 28% to ISO 4589. Low-temperature flexibility on the same sheets is -55°C to ISO 974. Neither figure appears on the straight, right-angle or Y sheets, which record self-extinguishing flammability and no cracking at low temperature without naming a temperature.

Fluid exposure and ageing, as published for the branch boots

ConditionTensile strengthElongation at breakMethod
As supplied≥15 MPa≥500%ASTM D2671
24 h at 23°C in gasoline≥11 MPa≥400%ASTM D2671
24 h at 23°C in diesel oil≥10 MPa≥350%ASTM D2671
24 h at 23°C in acid or alkali≥12 MPa≥400%ASTM D2671
168 h at 130°C, ageingNot published≥400%ASTM D2671

GHS2-N and GHS3-N only, reproduced from the manufacturer's 2-Way Boot datasheet, Issue 1, September 2024. The straight, right-angle and Y sheets carry no solvent figures at all. They answer fluids with a single rating of Good against MIL-I-81765A, which the standard page takes apart line by line.

What fitting over a mounted connector does to the build order

Every sheet in this family carries the same installation line, and its consequences sit upstream of the boot.

  • The connector is crimped, mated and tested first, so nothing is threaded onto the loom ahead of the termination.
  • A boot added late to a drawing does not re-sequence the build, because nothing has to pass through it before the connector exists.
  • Retrofit is a catalogued case rather than a workaround. The right-angle boot lists sealing over an already-mounted connector among its applications.
  • Rework runs the other way. A lined boot comes off with its bond, and the jacket is cleaned back before the replacement recovers onto it.
  • Clearance is checked against the band, not the figure. GHSB-111 publishes P at 38.00mm with ±10%, so a part in specification can measure 41.80mm.
  • The 120°C shrink temperature belongs to the material. Whatever is already inside the boot has to sit through it, and on a finished harness that is a connector and a crimp.

A boot is not a cable gland

A gland boot is asked for often enough to need answering here. A cable gland is a fitting: it threads into an enclosure wall, clamps the cable, and carries its own retention force and ingress rating. No harness boot sheet in these sources publishes a thread form, a clamping range, a retention figure or an IP number. What they publish is a bore pair, a length band and a material property set. So a boot insulates and strain-relieves at the cable. It does not hold the cable into a panel, and it will not stand in where a wall entry has to be certified. Where a boot is going over the back of a gland already fitted, the two diameters to send are the gland body and the jacket behind it.

Outlet count, exit angle, two diameters, lined or unlined

An enquiry answers in one reply when the lining decision travels with the geometry. Outlet count and exit angle, then the diameter over the connector and the diameter of the jacket behind it. Lined or unlined is the line most often missing, and the only one that cannot be revised after the boot has recovered.