Getting the right parts for your Webster & Bennett vertical boring mill starts with three pieces of information: the serial number, the series, and the table size. This guide shows you how to find all three.
Step 1: Find the Serial Number
The serial number plate is located on the end face of the cross slide — it is stamped or cast into the metal. This is the primary location. Secondary location: the headstock nameplate (but this can be missing or re-stamped after rebuilds).
The format is NNNN-S where NNNN is the machine number and S is the suffix (build batch). Example: 5416-3. The slash variant (5416/3) is identical.
Step 2: Determine the Series
The machine number (left of the dash) determines the series. This is critical because parts compatibility depends on the series.
| Series | Machine # Range | Era |
|---|
| Pre-DH / D | Up to ~5021 | Pre-1960s |
| Early DH | 5022 – 5232 | Late 1950s–Early 1960s |
| Series II DH | 5233 – 5441 | Mid 1960s |
| Series M / EM | 5442 – 6561 | Mid 1960s–1970s |
| Series V / EV / R | 6562+ | 1970s–1990s |
For the full guide with boundary warnings and detailed characteristics, see our
Series Identification Guide.
Step 3: Confirm the Table Size
The table size (diameter of the rotary table) is critical for clutch plate selection and several other parts. Common sizes: 36", 48", 60", 72". Check the speed plate on the control panel — the table diameter is usually listed there. If not visible, measure the table diameter directly.
Step 4: Check for Modifications
Always ask: "Has this machine been rebuilt or modified?" Many W&B machines have had clutch upgrades, hydraulic replacements, or CNC retrofits over their decades of service. A serial number does not guarantee original components. If the machine has been modified, provide photos when requesting parts — we can often identify non-standard components from photos.
Ready to Order Parts?
Once you have your serial number, series, and table size: