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ARP 156-2501 Harmonic Balancer Bolt Kit with Square Drive

Manufacturer

ARP

<h3>About ARP – Automotive Racing Products</h3><p>Few names carry as much weight in the performance fastener world as <strong>ARP</strong> — short for Automotive Racing Products. Back in 1968, racing enthusiast Gary Holzapfel noticed that many of his friends' broken engines were caused by fastener failure, and at the time no commercially available studs or bolts were up to the challenge — so he drew on his years of experience as a leading aerospace subcontractor and founded ARP. That problem-solving spirit has driven the company ever since.</p><p>From a backyard garage workshop, ARP has grown into a highly diversified manufacturer with 18 buildings across Southern California, totaling more than 275,000 square feet of forging, heat-treating, machining, quality control, finishing, and packaging facilities in Santa Paula and Ventura, California.</p><h3>Engineering That Goes Beyond &quot;Aerospace Quality&quot;</h3><p>ARP uses only top-quality materials — far above the usual &quot;aerospace quality&quot; others settle for — in a highly exacting manufacturing process to create fasteners with the strength and durability to last race after race. Fastener materials are available in 8740 Chrome Moly, ARP2000, and Custom Age 625+, each engineered for specific performance thresholds. In order to ensure optimum quality control, ARP controls all aspects of the manufacturing process entirely in-house — a discipline that has allowed it to build a reputation for &quot;zero defects&quot; quality throughout the industry.</p><p>Automotive Racing Products has achieved ISO 9001:2008 and AS9100 registration, certifications the company has maintained as a testament to its unwavering dedication to producing the highest quality fasteners available. ARP also operates an Aerospace Division and is one of the very few companies in the world fully licensed by the United States Government to manufacture MS-21250 fatigue-rated fasteners.</p><h3>Trusted by the World&apos;s Top Racing Programs</h3><p>ARP enjoys working relationships with professional engine builders and race teams across Formula 1, IndyCar, IMSA, NASCAR, NHRA, IHRA, Lucas Oil Late Model Dirt, and World of Outlaws — constant interaction that keeps ARP on the cutting edge of fastener technology. Whether you&apos;re building a weekend bracket racer or a full-time professional race engine, ARP has a solution engineered to hold things together under the most extreme conditions.</p><h3>ARP&apos;s Engine Fastener Lineup</h3><p>Today, ARP&apos;s product line contains thousands of part numbers and has expanded to include virtually every fastener found in an engine and driveline and throughout the suspension and frame. Among the most popular are <a href="/48-arp-engine-cylinder-head-bolt-set-10306">Engine Cylinder Head Bolt Sets</a>, <a href="/48-arp-engine-connecting-rod-bolt-5280">Engine Connecting Rod Bolts</a>, and complete <a href="/48-arp-engine-connecting-rod-5276">Engine Connecting Rods</a> — three categories that represent the critical fastening points where engine integrity is made or lost. ARP&apos;s High Performance series head bolt kits are rated at 170,000 psi — 15 percent stronger than Grade 8 fasteners — and are available with hex heads or reduced-wrenching 12-point heads that eliminate the need for valvetrain removal when re-torquing.</p><p>ARP stands behind its products indefinitely with respect to materials and workmanship, making every fastener a long-term investment in engine reliability rather than a consumable component.</p>

Part Number

156-2501
09/11/2036 4:18 AM
Sale Price

$29.99

In Stock (8)

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Usually delivered within 2 days

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Product Details

The ARP 156-2501 is a high-strength harmonic balancer bolt kit engineered to withstand the extreme kinetic energy absorbed by the balancer as the crankshaft flexes and twists. These ultra-strong bolts are rated at 200,000 psi tensile strength, allowing maximum clamping force to ensure the balancer remains locked in position under the most demanding conditions.

Key Features:

  • 200,000 psi tensile strength for superior clamping force
  • 12-point head design accepts deep sockets and resists stripping
  • 1/2" square drive forged into bolt head for engine rotation with standard 1/2" drive ratchet or breaker bar
  • 1/4" thick wide-area washer distributes load evenly
  • Extra tall head provides enhanced tool engagement
  • Constructed from heat-treated 8740 chrome moly steel
  • Heavy-duty black oxide finish for corrosion resistance

This square drive version combines the strength of ARP's premium balancer bolts with the convenience of a built-in 1/2" square drive, enabling easy rotation of the crankshaft assembly during engine building, installation, or maintenance procedures. The forged square drive eliminates the need for separate rotation tools while maintaining the bolt's structural integrity.

Products specifications

Overall Diameter

M12 x 1.50

Fastener Finish

Black oxide

Fastener Material

Chromemoly

Fastener Yield Strength (psi)

200,000 psi

Head Style

12-point

Quantity

Sold individually.

Socket

18mm

Thread Size

12mm x 1.50 RH

UHL

1.8

Underhead Length (in)

1.880 in.

Washer Included

Yes

So far so good. Ordering was seamless.

great

Great products and great delivery time

Good people

It's what I ordered

#1

Great turnaround time. Product was exactly what as displayed. Great service!!

Fast shipping cheapest I could find, easy to deal with, great product

All was good,except delivery wait time..it was longer than usual and delayed from the 8th to the 10th.

Very good deal and simple buying experience.

Very good prices and good shipping prices. found my parts cheaper then any place else. Thanks to Autoplicity for filling my order #8498 of 4/02/12 quickly and accurately. I will be back.

The item has not been delivered yet. But the email updates are great. And I found this much cheaper than elsewere.

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