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Small Farmer's Journal
PO Box 1627
Sisters, Oregon 97759
Mon - Thu, 8am - 4pm PDT

McCormick-Deering Tractor Disc Harrow No. 10-A

McCormick-Deering Tractor Disc Harrow No. 10-A

Small to mid-sized disc-harrows are a most useful tillage implement. Some farmers consider them indispensable. Discs such as the McD 10-A may be used with either tractors or big hitches of work horses. This tool will cut both plowed and unplowed ground. Ahead of the moldboard plow, the disc harrow is a valuable tool to cut up and free tough sod. When employed in tandem with spring tooth harrows, a great deal of work can be accomplished in much less time. Originally offered as a pamphlet to new owners of the implement, we offer this reprint unabridged because it may be helpful to someone struggling to make an old gang disc usable. SFJ



  • Remove all wires and arrange parts conveniently.
  • Oil all bearings and moving parts as you proceed and see that they work freely.
  • Bolts must be used in the holes in which they are found, or in parts to which they are attached, unless otherwise shown.
  • Shaded portions in the illustrations show parts to be assembled. These must be placed on the machine in the order numbered.
  • In the following instructions, wherever the terms “left” and “right” are used, it should be understood to mean from a position behind and facing the machine.



Front Harrow

(See Illustration No. 1)

  1. Attach front harrow frame to gangs with bolts located in bearings. Tighten nuts securely and spread cotters.
  2. Bolt draft angles, assembled with gang adjusting screw adjusting screw and set levers, to frame and cross bar as illustrated. Note: The gang adjusting screw bearing is furnished assembled in lower holes in adjusting screw standards. This bearing may be moved to upper holes, if more convenient for the operator (See “A”, Illustration No. 1.)
  3. Secure lower end of adjusting screw standard braces to frame angles. See that nuts on adjusting screw standard brace truss are tight.
  4. Slip set lever bars through slots in snubbing plate and secure to gang bearings with drilled bolts. Be sure bow in set lever bars is UP, exactly as illustrated. Attach set lever bars to set levers at the second (or inside) hole at front end of set lever bars for 5-ft. And 6-ft. Harrows, and at the end hole for 7-ft. And 8-ft Harrows. Tighten nuts securely and spread cotters.
  5. Secure inner and outer standard braces as shown.
  6. Attach scrapers to rear weight box angles as illustrated. The reinforcement plates go inside the weight box angle.

Rear Harrow

(See Illustration No. 2)

  1. Attach rear harrow frame to gangs with bolts located in bearings. Tighten nuts securely and spread cotters.
  2. Secure outer standard braces as illustrated.
  3. Attach outer draw bars, right and left, to inner gang bearings with bolts located in bearings. Attach draw bars to standards and weight box-angles as shown. Tighten nuts securely and spread cotters.
  4. Pass inner draw bars between swivel plates and straps and secure with drilled bolt, nut and cotter. Note: To obtain more or less angle to the rear gangs than the front, the bolt may be moved to the rear or front hole as required by the operator.
  5. Move front harrow into positions and attach rear harrow to front by means of bolts through connection eyes and weight box angles.
  6. Attach outer draw bar pressure brackets as shown. The cutting depth of the inner end of rear gangs may be controlled by raising or lowering the brackets.
  7. Attach scrapers to rear weight box angles as illustrated.


Power Gang Angling Attachment (Special)

This attachment is furnished in a complete unit and can be connected to the harrow by removing the draft angles and connections of the crank angling mechanism, and bolting the power angling attachment to front harrow frame and cross bar as shown in illustration. The set lever should be attached to set lever bars at the second (or inside) hole at the front end of set lever bars for 5 and 6 ft. Harrows, and at the end hole for 7 and 8 ft. Harrows. If necessary, readjust snubbing plate so that the gangs are held at the required working level.

To angle the gangs, pull the adjusting rope and move tractor ahead until the desired working angle is obtained. To straighten the gangs, back the tractor.




Rocking Scrapers (Special)

  1. Attach scrapers to rear weight box angles by means of bolts through scraper bar hanger. The reinforcement plate goes inside the angle (See “6”, Illustration No. 1.) The straight end of the scraper spring rests on the weight box angle. Hook the scraper spring in spring holder.
  2. Attach scraper lever and stop as illustrated. Set lock nuts on the stop so that the scraper blades come to the extreme edge of the disks when the scraper is rocked.
  3. Adjust scraper blades to just clear the disks when at center, by using the clamp near the scraper bar hanger. Fasten ropes as shown.


Full Blade Scrapers (Special)

Attach scraper bar, complete with scrapers, to rear weight box angles with bolts and space pipes. The space pipes go between the two angles.

Scrapers should be set (by means of bolts and slotted holes in scraper bar) to just clear the disk blades.

Center Tooth Attachment (Special)

(For Rear Harrow Only)

Bolt Center Tooth Attachment securely to rear harrow frame and cross bar angles, midway between the inner draw bars, as illustrated.

Note: For harrows equipped with 16” disk blades, the center tooth support bracket (P24325) is bolted to the angles with the offset UP, as illustrated. For 18” disk blades, P24325 is turned over and bolted to the angles with the offset DOWN.

Remove the inner draw bar swivel pins and attach the hitch to the tractor disk rear harrow by using the drilled bolts furnished with the hitch. Use the holes at the front end of the hitch angles that more nearly equal the distance between the inner draw bar swivel pin holes.

Adjust the hitch height by means of stop bolts and double nuts, the angles being held between the two nuts.



Keep all moving parts well lubricated when the harrow is in use. Use the grease gun supplied with the tractor.

For best results, the draft angles (front frame) on the front harrow should be approximately level when the harrow is hitched to the tractor. If necessary, adjust tractor draw bar to obtain this result.

In practically all field work the gangs should run level and cut at an even depth. Adjust the front harrow gangs to suit by raising or lowering the pressure plate at center of front harrow frame.

The rear gangs may be leveled by raising or lowering the outer draw bar pressure plates. If the harrow ridges the soil between the rear gangs, the soil may be leveled by raising the inner end of the gangs, or by giving them less angle by moving the rear harrow frame forward at the three holes in the inner draw bars.

If the rear gangs do not fill a center depression left by the front harrow, reverse the above adjustment.

The adjustment at the outer ends of the rear harrow frame is for spacing the rear gangs closer or farther apart to meet field conditions, or for changing the trailing position of the rear harrow. The adjustment is carefully set and locked in place at the factory to meet average conditions. If any change is necessary move both gangs outward.

For all field work the upper collar on the gang adjusting screw should be placed at the hole nearest the hand crank so that if the harrow is backed the gangs may straighten. With forward movement the gangs will again assume angle. (The lower hold, next to the crank bearing, is intended only for demonstration purposes.)

Spotlight On: Book Reviews

Old Man Farming

Spinning Ladders

You die off by passing away. You live on by passing on. I want to pass the culture of my life on slowly, over the ripening time of my best years.

Woodstove Cookery at Home on the Range

An Illustrated Guide To The Wood Fired Cookstove

Illustrated guide to the wood stove and it’s accoutrements.

An Introduction To Farm Woodlands

The farm woodland is that portion of the farm which either never was cleared for tillage or pasture, or was later given back to woods growth. Thus it occupies land that never was considered suitable, or later proved unsuitable, for farm enterprises.

Art of Working Horses Another Review

Art of Working Horses – Another Review

from issue:

One could loosely say this is a “how-to” book but it is more of an “existential” how-to: how to get yourself into a way of thinking about the world of working horses. Maybe we need to explain what a working horse is. A working horse is one, in harness, given to a specific task. So, in that context, the book illustrates the many ways Miller has worked with his equine partners over the years – helping them understand what he wants them to do, as both work together to create relationships that help achieve desired goals.

Work Horse Handbook

The Work Horse Handbook

The decision to depend on horses or mules in harness for farm work, logging, or highway work is an important one and should not be taken lightly. Aside from romantic notions of involvement in a picturesque scene, most of the considerations are serious.

Haying With Horses

Hitching Horses To A Mower

When hitching to the mower, first make sure it’s on level ground and out of gear. The cutter bar should be fastened up in the vertical or carrier position. This is for safety of all people in attendance during hitching.

Audels Gardeners and Growers Guide

How to Store Vegetables

Potatoes may be safely stored in bits on a well drained spot. Spread a layer of straw for the floor. Pile the potatoes in a long, rather than a round pile. Cover the pile with straw or hay a foot deep.

Training Workhorses Training Teamsters Driving Junipers Training

Driving: Juniper’s Training

A final sneak peak at the Second Edition of Lynn R. Miller’s “Training Workhorses / Training Teamsters.” Today’s excerpt, “Driving: Juniper’s Training,” is from Chapter 11, “Starting and Training Older Horses.”

Barbed Wire History and Varieties

Book Excerpt: The invention of barb wire was the most important event in the solution of the fence problem. The question of providing fencing material had become serious, even in the timbered portions of the country, while the great prairie region was almost wholly without resource, save the slow and expensive process of hedging. At this juncture came barb wire, which was at once seen to make a cheap, effective, and durable fence, rapidly built and easily moved.

Haying With Horses

Haying With Horses

If the reader is considering the construction of a barn we encourage you to give more than passing thought to allowing the structure of the gable to be open enough to accommodate the hanging of a trolley track. It is difficult or impossible to retrofit a truss-built barn, which may have many supports crisscrossing the inside gable, to receive hay jags. At least allowing for the option in a new construction design will leave the option for loose hay systems in the future.

Farmer Pirates & Dancing Cows

Farmer Pirates & Dancing Cows

From humor-filled stories of a life of farming to incisive examinations of food safety, from magical moments of the re-enchantment of agriculture to the benches we would use for the sharpening of our tools, Farmer Pirates & Dancing Cows offers a full meal of thought and reflection.

A Short History of the Horse-Drawn Mower

A Short History of the Horse-Drawn Mower

Book Excerpt: The enclosed gear, late model John Deere, Case, Oliver, David Bradley, and McCormick Deering International mowers I (we) are so fond of had a zenith of popular manufacture and use that lasted just short of 25 years. Millions of farmers with millions of mowers, built to have a serviceable life of 100 plus years, all pushed into the fence rows. I say, it was far too short of a period.

Art of Working Horses

Lynn Miller’s New Book: Art of Working Horses

Art of Working Horses, by Lynn R. Miller, follows on the heels of his other eight Work Horse Library titles. This book tells the inside story of how people today find success working horses and mules in harness, whether it be on farm fields, in the woods, or on the road. Over 500 photos and illustrations accompany an anecdote-rich text which makes a case for the future of true horsepower.

One Seed To Another: The New Small Farming

One Seed to Another

One Seed to Another is staggering and bracing in its truths and relevance. This is straight talk from a man whose every breath is poetry and whose heartbeat is directly plugged into farming as right livelihood.

Haltering Foals - Training Workhorses Training Teamsters

Haltering Foals

Lynn Miller’s highly regarded book, “Training Workhorses / Training Teamsters,” is back in print! And that’s not even the most exciting news: The Second Edition is in FULL COLOR! Today’s article, “Haltering Foals,” is an excerpt from Chapter 8, “Imprinting and Training New Born Foals.”

Build Your Own Earth Oven

An Introduction To Cob

Mixed with sand, water, and straw, a clayey-subsoil will dry into a very hard and durable material; indeed, it was the first, natural “concrete”. In the Americas, we call it “adobe”, which is originally from the Arabic “al-toba”, meaning “the brick.” Invading Moors brought the word to Spain from North Africa, where an ancient mud building tradition continues today.

Apples of North America

Freedom has been called the ugly duckling of disease-resistant apple varieties. But that shouldn’t detract from its many merits. These include the freedom from apple-scab infection for which it was named, a high rate of productivity, and an ability to serve as a good pollinator for its more attractive sibling, Liberty.

Small Farmer's Journal

Small Farmer's Journal
PO Box 1627
Sisters, Oregon 97759
Mon - Thu, 8am - 4pm PDT