DIN 608 Plow Bolts / Flat Countersunk Square Neck Bolts – Grade 8.8 / 10.9 (High Tensile) – Manufacturer Direct

High-Performance DIN 608 Plow Bolts: The Standard for Agricultural Machinery

At Handan Bolt, we are a specialized manufacturer of DIN 608 Flat Countersunk Head Square Neck Bolts, widely recognized in the agricultural and construction sectors as Plow Bolts. Produced in our dedicated heat-treatment facility in Yongnian, China, these bolts are engineered to survive in the harshest environments—specifically the abrasive soil conditions faced by farming equipment. We supply major OEM tractor brands and aftermarket parts distributors with bolts that offer superior wear resistance and impact strength.

What is a Plow Bolt (DIN 608)?

A Plow Bolt is a specialized fastener designed to sit flush with the surface of the part it secures. It features a flat, tapered Plow (Read more on Wikipedia) head (countersunk) and a square neck directly beneath the head.

• Flush Fit Design: The countersunk head ensures that once installed, the bolt head does not protrude. In agricultural applications (like on a plowshare or moldboard), this allows soil to flow smoothly over the surface without obstruction or wear on the bolt head.
• Square Neck Locking: The square neck fits into a corresponding square hole in the steel blade. This locks the bolt in place, preventing it from spinning while the nut is tightened or when the equipment is vibrating during operation.

Material Grades: Built for Abrasion Resistance

Since these bolts are often the only thing holding a heavy steel plow blade to the machine, strength is critical. We manufacture primarily in high-tensile grades:

1. Grade 8.8 & 10.9 (High Tensile)

This is our standard for plow bolts. We use high-quality alloy steel (like 40Cr or 35Crmo) which is quenched and tempered.

• Why High Grade? Lower grade bolts (like 4.8) will shear off or stretch when hitting a rock in the field. Our Grade 8.8 and 10.9 bolts provide the high shear strength needed to withstand impact loads from rocks and hard-packed soil.

2. Grade 4.8 (Mild Steel)

For lighter applications, such as lawn mowers or light-duty gardening equipment, we also supply cost-effective Grade 4.8 bolts.

Surface Finishes

To resist rust and corrosion in damp fields, we offer several finishes:

• Black Oxide (Oiled): The most common finish for Grade 10.9 plow bolts. The oil provides basic shelf-life protection, and the black color matches most agricultural blades.
• Zinc Plated (Yellow/Clear): Provides galvanic rust protection. Yellow Zinc is particularly popular in the aftermarket parts industry for its distinctive look.
• Hot Dip Galvanized (HDG): For extreme conditions, we can provide HDG coatings, though care is taken to ensure the nut fits the thicker coating properly.

Common Applications

Our DIN 608 Plow Bolts are compatible with a wide range of machinery:

• Agricultural Equipment: Attaching plowshares, moldboards, cultivator points, and harrow discs to tractors.
• Construction Machinery: Securing cutting edges / grader blades on bulldozers, excavators, and snowplows.
• Mining: Wear liners in chutes and crushers where a flush surface is required.

Why Source from Handan Bolt?

Perfect Fit: We strictly control the head angle and countersunk depth to ensure a perfectly flush fit with standard blades.
Heat Treatment Expertise: Our in-house heat treatment ensures the core hardness is sufficient to prevent snapping, while the surface is hard enough to resist abrasive wear.
Global Export: We are experienced in supplying “Plow Bolts” to the USA, Brazil, Russia, and European markets.

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