The best M12 x 1.25 bolt depends on its length, strength class, head style, and application. The RemTune bolt is best for a single 40 mm, Grade 10.9 flange fastener; the BoltsandNuts.com set is better when you need four shorter Grade 10.9 bolts. The YD-PS001 option offers several lengths in Grade 8.8, while the METALLIXITY pack provides five fully threaded bolts. ECCPP is a vehicle-specific wheel fastener set, not a general-purpose bolt selection.
| Product | Best suited for | Key detail |
|---|---|---|
| RemTune Store M12 x 40 mm | Single high-strength flange bolt | Grade 10.9, zinc-plated |
| YD-PS001 Store M12 x 1.25 | Length selection | Grade 8.8, multiple lengths listed |
| BoltsandNuts.com M12 x 30 mm | Small multi-bolt jobs | Four Grade 10.9 bolts |
| ECCPP M12 x 1.25 wheel set | Specified vehicle wheel applications | 20 wheel fasteners, 28 mm shank |
| METALLIXITY M12 x 35 mm | General repairs requiring full threads | Five carbon-steel bolts |
RemTune M12 x 40 mm Grade 10.9 Flange Bolt
This is a single, partially threaded M12 x 1.25 bolt with a 40 mm length. Its listed Grade 10.9 carbon-steel construction is intended for higher-strength fastening needs than Grade 8.8 options. Zinc plating is specified for corrosion resistance, and the JIS B1189-style flange head has a 17 mm hex size.
Best for: Buyers who need one 40 mm flange bolt and prioritize a Grade 10.9 specification. The integrated flange spreads the load, so a separate washer may not be needed when the joint design permits it. Limitation: The listing describes it as partially threaded, so check the unthreaded section against the joint before ordering.
YD-PS001 M12 x 1.25 Zinc Flange Bolt
The listed fastener has a 12 mm diameter, a 1.25 mm fine-thread pitch, and Grade 8.8 zinc construction. The product name offers lengths from 25 mm through 90 mm, including 30, 40, 50, and 60 mm options. Confirm the selected length in the listing before purchase.
Best for: Buyers who need a Grade 8.8 bolt and want to choose from several listed lengths. It is a better fit than a fixed-length single bolt when the required length is known but varies by project. Limitation: The provided features do not specify the selected bolt’s head dimensions, threading extent, or package quantity.
BoltsandNuts.com Four-Piece M12 x 30 mm Set
This pack includes four M12 x 1.25 bolts with a 30 mm length measured under the head. The listing specifies Class 10.9, a 17 mm wrench size, JIS-style hex flange heads, and a zinc-clear finish. It is a compact option when a repair requires several matching fasteners.
Best for: Buyers who need four short, high-strength flange bolts with the same dimensions. The pack quantity and stated length make it easier to match a multi-fastener job than buying a single bolt. Limitation: At 30 mm, it may be too short for assemblies requiring deeper engagement or a thicker clamping stack.
ECCPP M12 x 1.25 Vehicle Wheel Fastener Set
This 20-piece set is listed for specified Jeep, Chrysler, Fiat, and Dodge applications. Features include M12 x 1.25 threads, a 28 mm shank, 17 mm hex, a 60-degree conical seat, and 35CrMo material. The product information limits some listed fitments to aluminum wheels and says the wheel seat must match the fastener.
Best for: Buyers replacing wheel fasteners who have verified the vehicle, wheel type, thread, shank, and seat requirements. It was selected because it matches the M12 x 1.25 search, but it is not a general-purpose machine bolt. Limitation: Do not assume fitment from thread size alone; the listing excludes iron wheels for certain applications.
METALLIXITY M12 x 35 mm Fully Threaded Bolts
This five-piece pack is described as fully threaded carbon-steel hex bolts with a 35 mm length and 1.25 mm pitch. The listing also specifies Grade 8.8 and a 19 mm hex head. Suggested uses include furniture repair, appliances, communications equipment, and machinery.
Best for: Buyers who need several fully threaded bolts for general repairs and whose project accepts the listed head size. Limitation: The product title also says “coarse thread UNC,” which conflicts with the stated 1.25 mm metric pitch. Verify the thread specification with the seller before relying on it.
Buying Guide: How to Choose an M12 x 1.25 Bolt
What does M12 x 1.25 mean?
M12 identifies a nominal 12 mm metric thread diameter. The 1.25 figure is the distance between thread peaks in millimeters, commonly called the pitch. Match both diameter and pitch to the mating threads; a bolt that has the correct diameter but a different pitch may damage the joint.
Which length and thread style should you choose?
Measure the required length according to the product’s stated convention. For example, the four-piece set specifies length under the head. Also check whether the bolt is fully or partially threaded. A partially threaded bolt may be unsuitable if the joint needs threads along the entire engagement area.
Is Grade 8.8 or Grade 10.9 better?
These are different strength classes, not a universal ranking for every repair. Use the class required by the equipment or engineering specification. Do not substitute a higher class automatically: the joint design, material, and tightening requirements still matter.
When does the head and finish matter?
A flange head can distribute load over a wider area, while a standard hex head may require a separate washer depending on the assembly. Zinc plating is listed on several products, but the provided details do not establish suitability for every outdoor or corrosive environment. Check the application requirements.
Frequently Asked Questions
Is M12 x 1.25 a fine thread?
It is a metric thread with a 1.25 mm pitch. Product listings may describe it as fine thread, but confirm that the mating part calls for this exact pitch.
Can I use an M12 x 1.25 bolt in place of an M12 x 1.5 bolt?
No. Both have a nominal 12 mm diameter, but their pitches differ. Use the pitch specified for the mating threads.
Does a flange bolt always eliminate the need for a washer?
No. An integrated flange spreads load, but whether it replaces a washer depends on the joint and the manufacturer’s requirements.
Are wheel fasteners interchangeable with regular bolts?
No. Wheel fasteners depend on vehicle fitment and details such as seat shape, shank length, and wheel type. Verify all of these before installation.
Should I choose a fully threaded bolt?
Choose one when the joint requires threads along the bolt’s length. If the design calls for an unthreaded shank through part of the joint, select a partially threaded bolt with suitable dimensions.