Quick answer
To correctly size and select an M16-2 x 150mm socket cap screw, match thread pitch (2mm), length (150mm), drive type (hex socket), and material (316 stainless steel) to your application's load and environment requirements.
Why thread pitch and length matter
The M16-2 designation means a 16mm diameter with a 2mm thread pitch—a coarse metric thread. Coarse threads are standard for general fastening in machinery because they resist stripping and install quickly. The 150mm length must fully engage the mating threads without bottoming out. A common mistake is assuming all M16 bolts use the same pitch; fine-pitch M16x1.5 exists and is not interchangeable.
For fully threaded screws like this one, the threads run the entire shank. This provides maximum grip length but reduces shear strength slightly compared to a partially threaded screw with a solid shank. Choose fully threaded when you need clamping over the full length, such as in jigs or adjustable assemblies.
316 stainless steel: corrosion resistance vs. strength
316 stainless steel offers superior corrosion resistance compared to 304 or 18/8 grades, especially in marine or chemical environments. However, it has lower tensile strength than alloy steel grades like Grade 8 or 12.9. For high-stress structural connections where corrosion is not a concern, a hardened steel screw may be more appropriate.
When using 316 stainless, avoid mixing with carbon steel nuts or washers in wet environments—galvanic corrosion can occur. Also, 316 stainless can gall (cold-weld) during installation; applying a light anti-seize lubricant to the threads prevents this.
How to size and select M16-2 x 150mm socket cap screws
- 1. Confirm thread pitch and diameter: Measure the screw diameter (16mm) and thread pitch (2mm) using a caliper and thread gauge. The pitch is the distance between thread crests. M16-2 is a coarse thread—do not substitute with M16x1.5 fine pitch. Common mistake: using a fine-pitch nut on a coarse-thread screw will damage threads.
- 2. Verify length and thread engagement: Measure the screw length (150mm) from under the head to the tip. Ensure the threaded portion will engage at least 1.5 times the screw diameter (24mm) into the mating material. For fully threaded screws, the entire 150mm is available for engagement. Checkpoint: if the screw bottoms out before tightening, either shorten the screw or add a washer to prevent damage.
- 3. Select the correct drive type: These screws use a hex socket drive (Allen key). Use a properly sized hex bit (typically 8mm for M16) to avoid stripping the socket. Ball-end hex keys allow angled entry but reduce torque capacity—use straight hex keys for final tightening. Common mistake: using a worn or incorrect-size hex key will round out the socket and ruin the screw.
- 4. Match material to environment and load: 316 stainless steel is ideal for wet, salty, or chemical-exposed applications. For high-tensile structural loads (above 80% of proof strength), consider alloy steel screws instead. Check the screw's proof load rating against your clamping force requirements. Checkpoint: if the application involves repeated disassembly, apply anti-seize to 316 stainless threads to prevent galling.
- 5. Install with proper torque: Use a torque wrench set to the manufacturer's recommended value for M16-2 316 stainless steel socket cap screws (typically around 170-200 Nm, but verify with the supplier). Over-tightening can strip threads or cause screw failure; under-tightening leads to loosening under vibration. Common mistake: assuming torque values for steel screws apply to stainless—stainless has different friction properties and may require lower torque.
Product details
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M16-2 X 150mm Socket Cap Screws | Hex Socket Drive | Fully Threaded | 316 Stainless Steel (25 / Pkg.): These M16-2 x 150mm socket cap screws are manufactured from 316 Stainless Steel, featuring a hex socket drive. They are fully threaded and designed for machinery, tooling, jigs, and precision assemblies. The 316 stainless steel construction provides excellent corrosion resistance for demanding environments, while the hex socket drive allows for high torque application without cam-out.
M16-2 X 150mm Socket Cap Screws | Hex Socket Drive | Fully Threaded | 316 Stainless Steel (25 / Pkg.)