No number, no label, no paperwork
Replacing a boot when the part number is gone
A fitted boot measuring 43mm across the mouth points at one catalogued row: GRB-1, 78mm as supplied to 35mm recovered, with two 4.0mm walls in between.
Three corrections before a chart will take your figure
You are measuring the outside of a moulding. The charts are indexed on the inside. The bushing boot sheet prints its own legend and says so: D and d are internal diameters.
Two walls sit between those numbers. GRB-1 publishes T at 4.0mm, banded ±10%, so two walls are 7.2mm to 8.8mm. A 43mm outside mouth is 34.2mm to 35.8mm inside.
That band falls on one row. GRB-1 closes to 35mm; GRB-2 and GRB-2A stop at 37mm and GRB-3 at 72mm. One corrected reading rules out three quarters of the family.
Recovery is the second correction. Every b and every f figure is measured with nothing inside the moulding, which is what free recovery means. Your boot stopped where the bushing stopped it, so its figure sits above f and below s.
Length is the third. GRB-1 publishes 160mm as supplied and 130mm recovered. A moulding pulls in along its axis too, so a fitted length is already the short number.
What one corrected diameter rules out
| Family | Sizes | Wide end, as supplied → recovered | Narrow end, as supplied → recovered | Full chart |
|---|---|---|---|---|
| GHSB harness straight | 3 | 25.60 → 10.30 up to 37.00 → 20.00 | 23.80 → 4.70 up to 37.00 → 8.40 | Right angle and straight |
| GHRB harness right angle | 2 | 25.70 → 10.50 up to 43.00 → 26.00 | 22.00 → 4.80 up to 41.00 → 10.00 | Right angle and straight |
| GHS2-N two-outlet | 3 | 13.5 → 6 up to 39 → 18 | 6.6 → 3.3 up to 27 → 12.4 | Boots by outlet count |
| GRB bushing right angle | 4 | 78 → 35 up to 145 → 72 | 34 → 16 up to 67 → 34 | Busbar and bus-duct |
| GSB bushing straight | 4 | 80 → 34 up to 140 → 65 | 34 → 21 up to 90 → 33 | Busbar and bus-duct |
Internal diameters in mm, and the published extremes of each chart rather than a continuous range. Intermediate sizes exist inside every span.
Six figures off the part itself
The recording order is this site's; every chart figure it points at is the manufacturer's. Four of the six disappear when the old moulding comes off, so they come first.
Entry bore, at the wide end
Callipers across the mouth, outside to outside, at the widest point. The outside figure and the wall go in as two numbers, never as one derived bore.
Exit bore, where the cable leaves
The same reading at the cable end, on the moulding and not on the cable. It eliminates rows fastest: the harness charts bottom out at 4.70mm recovered, the bushing charts at 16mm.
Overall length, end to end
Along the axis, ignoring the cable. The harness charts call this P and band it ±10% — 5.20mm either way on the 52.00mm published for GHRB-151.
Leg lengths, one at a time
One overall figure will not index these charts. The straight bushing chart publishes A, L and B separately; the harness charts publish P and R; the two-outlet chart L1, L2 and L3.
Wall thickness, at a cut edge
Readable only once the boot is off or split. It converts every outside measurement into an internal one, and it carries the loosest band on the sheet.
Exit angle, photographed against a rule
Straight or 90° is the fastest single filter here, and a photograph settles it where a sentence does not. A steel rule along the cable, the shot square to both legs.
What the lining, the wall and the feel tell you
- Red inside the mouth
- Water-resistant red mastic, named by colour on the bushing boots GRB and GSB and on the semi-conductive breakout family.
- A lining that is not red
- The low-voltage breakout family is hot-melt-adhesive lined and the sheets give it no colour, so absence of red narrows the field without naming it. The outlet boots are catalogued with or without lining, which leaves a bare one inconclusive.
- A wall over 3.6mm
- Bushing territory. No harness chart in this pack publishes a wall above 3.00mm, and no bushing chart below 3.6mm. That gap survives the loss of every marking.
- Semi-rigid, and black
- The two-outlet and three-outlet boots are published at 90±2 Shore A, standard colour black. The straight and right angle sheets publish neither figure.
- No lining, and it came off intact
- Then nothing was ever shrunk. The reusable insulating boot is a modified silicon/rubber shroud, catalogued on a bushing diameter of 46 to 70mm. A different family.
- Cores separating, not a connector
- Then it is a breakout, indexed on core count rather than outlet count. Which one you hold.
No cross-reference table is published here, and none should be trusted
Nothing in this pack sets one manufacturer's boot codes against another's, and this site does not build that table itself. A part number holds no bore pair, no wall and no angle — the three things deciding whether a replacement goes on and stays on. Where a rival code has genuinely been matched to a catalogued row, someone did that holding both parts. Any site converting a code into an equivalent without the figures is guessing at your cost.
When the geometry turns out not to be catalogued
Five families and sixteen sizes do not cover every shape ever moulded, and a corrected figure outside every span above is a real answer rather than a measuring error. Two published routes remain. Custom dimensions and special flame-retardant builds are offered on the low-voltage breakout family, stated on that sheet and on no boot sheet. And the reusable rubber boot sells on range-taking capability rather than a fixed pair.
Asked by people holding an unmarked part
Is a shrink boot adapter the same thing as the boot?
The old boot measures 35mm. Which size is that?
Does the replacement have to be the same part?
It was cut off before anyone measured it. What now?
Six figures and one photograph, in one message
An enquiry carrying the entry bore, the exit bore, the wall, the length, each leg and the exit angle can be worked against a chart by whoever reads it. A part number cannot.