Grade 8
Plow Nut
UNC plow nut in Grade 8 for securing plow bolts on earthmoving cutting edges.
About the Plow Nut
Plow nuts (plough nuts) go on the back of plow bolts to clamp cutting edges and end bits to grader, dozer and loader blades and buckets. They are grade 8 UNC hex nuts in plain finish, in every plow bolt diameter from 3/8 to 1-3/8 inch, in Hobson's packs from 500 down to 35. Choose the diameter above; the guide below matches each nut to its plow bolt and explains why it is not a grade 9 nut.
Also called plough nuts or cutting edge nuts.
Features
- UNC thread
- Grade 8 high strength
- Plain finish
- HEC specification
- Pairs with plow bolts
- Imperial sizes 3/8" to 1-3/8"
Applications
- Earthmoving cutting edges
- Securing plow bolts on blades
- Heavy machinery
What plow nuts are for
A plow nut is the nut on the back of a plow bolt. The plow bolt's countersunk head sits flush in the cutting edge and its square neck stops it turning, so the nut is the part you turn to clamp the edge to the blade or bucket. Hobson lists its plow bolts and nuts for securing the cutting edges of earthmoving blades. These are used on grader, dozer and loader cutting edges and end bits, bucket edges, and plough shares and points.
Hobson's plow nuts are hex nuts in grade 8, plain finish, with UNC (coarse) threads, made to Hobson's own (HEC) specification. They suit UNC plow bolts of the same diameter. Track nuts are a different part: Hobson's track nuts are UNF and metric fine, for track shoe bolts.
Plow nut sizes, threads and packs
Match the nut to the diameter and thread of the plow bolt. Select a row to open that nut in the selector.
Every plow nut we carry, smallest to largest. Diameter in inches; thread and TPI (threads per inch) from Hobson's data, all UNC. Cross reference is the QFind number on Hobson's plow nut Did You Know sheet (1702111DYK), where it gives one. Pack is Hobson's pack and the minimum order. Plow bolt grades are those in our plow bolt range. Nuts are grade 8 only; see the grade note below for grade 9 bolts. Tap a number to show it in the selector above.
| Plow nut | Thread | Our plow bolts in this thread | Cross reference (QFind) | Pack |
|---|---|---|---|---|
| 3/8" | 3/8-16 UNC | Grade 8 plow bolts | None given | 500 |
| 7/16" | 7/16-14 UNC | Grade 8 plow bolts | None given | 500 |
| 1/2" | 1/2-13 UNC | Grade 8 plow bolts | None given | 200 |
| 5/8" | 5/8-11 UNC | Grade 9 plow bolts (not a grade 9 nut, see below) | 4K-0367 | 400 |
| 3/4" | 3/4-10 UNC | Grade 9 plow bolts (not a grade 9 nut, see below) | 2J-3506 | 250 |
| 7/8" | 7/8-9 UNC | Grade 9 plow bolts (not a grade 9 nut, see below) | 2J-3505 | 150 |
| 1" | 1-8 UNC | Grade 9 plow bolts, incl. the long shoulder (not a grade 9 nut, see below) | 2J-3507 | 100 |
| 1-1/4" | 1-1/4-7 UNC | Grade 9 plow bolts (not a grade 9 nut, see below) | 3K-9770 | 50 |
| 1-3/8" | 1-3/8-6 UNC | Grade 9 plow bolts (not a grade 9 nut, see below) | 9M-3770 | 35 |
Grade 8 plow nuts, and grade 9 plow bolts
Hobson's plow nuts are grade 8 only; Hobson lists no grade 9 plow nut. In our range they match the grade 8 plow bolts (3/8, 7/16 and 1/2 inch) in grade and thread.
From 5/8 inch up our plow bolts are grade 9. The nuts share their UNC threads, but they are not a grade 9 nut, and Hobson's grade 9 plow bolt torque sheet gives figures for the bolts without stating a nut grade. So don't treat these nuts as a grade 9 match or tighten them to the grade 9 bolt torques on that sheet: use the nut and the torque the cutting edge or machine maker specifies. Hobson publishes no strength, proof load or torque figures for its plow nuts.
Fitting plow nuts to a cutting edge
- Clean the countersunk holes in the edge and the holes in the blade, and line them up.
- Push each plow bolt through from the wearing face so the head sits in the countersink and the square neck locates in the square hole.
- Run a plow nut of the same diameter and thread onto each bolt from the back by hand, with a washer only if the edge maker specifies one.
- Tighten to the edge or machine maker's torque. Hobson's plow bolt torques are for grade 9 bolts, plain and lightly oiled, on a first tightening, and state no nut grade.
Plain finish
Hobson supplies plow nuts plain: no coating, lightly oiled to inhibit rust in the packaging and assist installation. That matches Hobson's plow bolts, which are also plain. None of our plow nuts is galvanised, zinc plated or stainless.
Plow nuts in Adelaide
Allmat supplies plow nuts, plow bolts and track fasteners to earthmoving contractors, plant operators, farmers and fitters across Adelaide and South Australia. Add the nuts to a quote with the bolts and the rest of your list, and we will price the lot.
Plow nuts for blades and cutting edges
Plow nuts, plow bolts, track bolts and track nuts are available to order from Allmat for earthmoving contractors, plant operators, farmers, fitters and trade across Adelaide and South Australia. Order through Allmat, we pick and pack it, then click and collect from the Allmat yard or have it delivered to site.
Goes with
Questions
What is a plow nut?
The hex nut that goes on the back of a plow bolt to clamp a cutting edge to an earthmoving blade or bucket. Hobson's are grade 8, plain finish, with UNC threads.
What size plow nut do I need?
The same diameter and thread as the plow bolt: 3/8, 7/16, 1/2, 5/8, 3/4, 7/8, 1, 1-1/4 or 1-3/8 inch, all UNC.
Is there a grade 9 plow nut?
Hobson lists none: its plow nuts are grade 8. Hobson's grade 9 plow bolt torque sheet states no nut grade, so for grade 9 plow bolts use the nut and torque the cutting edge or machine maker specifies.
What thread is on a plow nut?
UNC: 16 TPI on 3/8, 14 on 7/16, 13 on 1/2, 11 on 5/8, 10 on 3/4, 9 on 7/8, 8 on 1 inch, 7 on 1-1/4 and 6 on 1-3/8 inch.
How many plow nuts are in a pack?
500 of the 3/8 and 7/16 inch, 200 of the 1/2, 400 of the 5/8, 250 of the 3/4, 150 of the 7/8, 100 of the 1 inch, 50 of the 1-1/4 and 35 of the 1-3/8 inch. The pack is the minimum order.
Are plow nuts and track nuts the same?
No. Hobson's plow nuts are UNC hex nuts for plow bolts. Its track nuts are mostly UNF or metric fine, for track bolts on track shoes.
Where can I buy plow nuts in Adelaide?
Order through Allmat. Order ahead by phone on 1300 03 03 63 or send your list for a quote, then click and collect from 25 Kapara Road, Gillman, or have them delivered to site.
Plow Nut: sizes and finishes we supply
9 lines by finish. Pick one above for its product code and pack sizes.
| Finish | Sizes | Lines |
|---|---|---|
| Steel | 3/8, 7/16, 1/2, 5/8, 3/4, 7/8, 1, 1-1/4, 1-3/8 | 9 |
Data sheets and documents
The documents for the product you choose are listed with the selector above. Here is every Plow Nut document from Hobson Engineering.
All Plow Nut documents (4)
Data sheets and technical data (2)
Did You Know flyers (1)
Guides and articles (1)
Need them in bulk?
Add the sizes you need to your quote, or send us your list and we’ll price the lot and supply it with the rest of your order.
Browse all nuts