The first question in any JOMA-style blade order is not which segment looks right; it is how the segments cover the moldboard. A plow with a 96-inch moldboard does not automatically take two 48-inch sections, because the working width, the end clearance, and the mounting pattern all enter the calculation. Matching the segments to the moldboard is a measurement and arithmetic exercise, and it is the step that prevents a warehouse full of the wrong sections.
This article explains how to match JOMA-style blade segments to moldboard width: the standard segment sizes and weights, the segment-count calculation, how to handle non-standard widths, and how to measure and verify before ordering.
Blade width starts with the moldboard
The moldboard width is the reference for the whole calculation, and “width” means the working width the sections must cover, not the marketing name of the plow. A 10-foot plow may have a moldboard that measures slightly different from another 10-foot model, so the measurement comes from the actual plow, not from the model number.
Measure the moldboard’s cutting-edge mounting width: the distance the edge sections must span, measured straight across. Note the position of the end holes and the hardware, because the sections have to fit between the ends and align with the mounting.
The measurement should be taken twice, with the plow level and supported, and recorded in the same units the manufacturer uses. The numbers that go into the calculation have to be trusted, because every later decision depends on them.
What are the standard segment sizes and weights?
SENTHAI’s JOMA-style line publishes standard section sizes and weights that the calculation starts from:
| Item | Size | Weight |
|---|---|---|
| 4-foot snow plow section | 48″ x 6″ x 7/8″ (1219 x 152 x 23 mm) | 17.5 kg |
| 3-foot snow plow section | 36″ x 6″ x 7/8″ (914 x 152 x 23 mm) | 13.1 kg |
| Cast steel segment (horseshoe design) | 11.22″ x 5″ x 3/4″ (285 x 127 x 19 mm) | 3.5 kg |
| Carbide insert | 1″ x .95″ x 0.32″ (25.9 x 24.25 x 8.16 mm) | 70 g |
The sizes are the building blocks of the combination plan. The weights matter for handling and for the plow’s lift capacity, so the combination calculation should include the total weight of the chosen sections, not just the coverage.
A simple segment-count calculation
The calculation is straightforward once the working width and the standard lengths are known.
Divide the moldboard working width by the standard segment length to get the starting count. For a 96-inch working width with 48-inch sections, the starting count is two; for 108 inches, it is two 48-inch sections plus a 12-inch allowance to manage.
The remainder is where the judgment comes in. A working width that does not divide evenly by the standard length leaves a gap or an overhang, and the plan has to decide how to cover it:
- Use a shorter standard section if one fits the remainder;
- Use a custom section for the end position;
- Accept a small end gap if the hardware and the plow design allow it.
The calculation should also account for the end-hole offsets and the clamping arrangement, because the sections do not butt flush at the very ends in every mounting system. The arithmetic on paper is the starting point; the drawing confirmation is the contract.
The calculation also has to respect the hardware. The clamp bars span the joints between sections in many systems, so the joint positions have to land where the hardware can hold them. A combination that covers the width perfectly but places a joint under a clamp that is not designed for it will fail in the field, which is why the combination plan and the hardware plan are drawn together.
If the sections would overlap the moldboard ends, that is a fit problem, not an option: the end sections should align with the working width, and the plan should account for the end clearance rather than leaving the ends to overhang or gap. The end condition is one of the details the drawing confirmation has to settle, because it decides whether the combination is a fit or a compromise.
How do you handle non-standard widths?
Non-standard widths are normal in real fleets, and the options are the same in every case:
- Custom section lengths: SENTHAI states it can manufacture to drawings, samples, or specifications, so the end section can be made to the exact width;
- Mixed standard sizes: a combination of 3-foot and 4-foot sections can cover many widths without custom work;
- End-section solutions: the last position can use a custom or adapted section while the main span uses standards.
The choice between custom and mixed-standard depends on quantity and cost. A single plow with an odd width is usually cheaper to cover with a custom end section than to re-specify the whole span; a fleet of identical plows justifies the custom plan. The manufacturer’s engineering team should confirm the combination and the drawing before production.
Measuring and verifying before ordering
Before the order, verify the plan against the plow:
- Re-measure the moldboard working width and record the date;
- Check the end-hole positions and the hardware against the planned sections;
- Confirm the section lengths and hole patterns on the drawing;
- Verify the total weight against the plow’s lift capacity;
- Send the measurements and the plow model to the manufacturer for the drawing confirmation.
The verification catches the errors that the paper calculation misses: a moldboard measured on a slope, a hardware position that shifts the end section, or a lift capacity that the heavier combination exceeds. The ten minutes of verification are cheaper than the wrong order.
The verification should also be repeated for each plow model in the fleet. Two plows of the same model can measure differently after years of service, because the moldboard has been bent, welded, or modified, and the modification changes the width the sections must cover. Measuring each unit, or at least sampling each model and flagging the ones that differ, protects the order from the assumption that identical models have identical widths.
The same care applies to the fleet’s future plans. If new plows or new moldboards are scheduled, the segment plan should be confirmed against the new equipment as well, because the width that fits today’s fleet may not fit next season’s. A segment plan that is reviewed when the fleet changes is a plan that stays correct.
The measurement habit should also be documented in the fleet’s standard: a one-page form with the plow model, the measured width, the date, and the person who measured. The form makes the measurement repeatable and auditable, and it gives the next order a record instead of a memory.
The record also survives staff changes, which is what keeps the segment plan accurate for the fleet.
And the plan is only as good as the measurement behind it.
Send your width for a segment plan
The practical next step is to send the measured width, the plow model, and the mounting details to the manufacturer and ask for the segment plan. SENTHAI’s JOMA-style blade page is the product reference, the snow plow product range shows the families, and the contact page is where the plan request starts.
The segment plan comes back as a drawing-based confirmation: the section lengths, the count, the hole patterns, and the combination across the moldboard. That confirmation, not the arithmetic on a notepad, is what the order should be built on.
Expert view — SENTHAI engineering team: “Measure twice, order once. The moldboard width and the hardware are the facts the segment plan is built on.”
Frequently Asked Questions
What measurement do I need for the segment plan? The moldboard’s cutting-edge mounting width, measured straight across with the plow level, plus the end-hole positions and the hardware details.
What are the standard JOMA section sizes? SENTHAI publishes 4-foot (48″ x 6″ x 7/8″, 17.5 kg) and 3-foot (36″ x 6″ x 7/8″, 13.1 kg) sections, plus cast steel segments and carbide inserts.
How do I calculate how many sections I need? Divide the working width by the standard section length, then manage the remainder with a shorter standard, a custom end section, or an accepted gap confirmed on the drawing.
Can I mix 3-foot and 4-foot sections? Yes, a combination of standard sizes covers many widths without custom work. The combination plan should be confirmed on the drawing.
What if my width is non-standard? Use a custom end section, a mixed-standard combination, or a fully custom plan. SENTHAI manufactures to drawings, samples, or specifications.
Why does the weight matter? The section weights add up across the plow, and the total must stay within the plow’s lift capacity. The plan should include the weight calculation.
What should I send the manufacturer? The measured width, the plow model, the mounting and hardware details, and the target quantity. The drawing-based confirmation is the order basis.
Sources
- SENTHAI – JOMA Style Blade product page
- SENTHAI – Snow Plow products
- SENTHAI – Official website
- SENTHAI – Contact and quotation
- FHWA – Road Weather Management
- AASHTO – Winter maintenance resources