SPECIFICATIONS: The Bike Stem Bolts have an M6x18mm specification. M6 refers to the bolt's diameter, which is 6 millimeters, and 18mm indicates the length of the bolt. （Please note: This is not the M5 specification.） MATERIAL: These Bike Stem Bolts are made of 10B21, known for its excellent corrosion resistance and durability. The alloy steel construction ensures long-term reliability of the bolts in various environmental conditions. HIGH STRENGTH: These bolts are specially designed and manufactured to provide exceptional strength and reliability. They can withstand high pressure and loads, ensuring stability and safety for your bike's stem. PRECISION THREADING: The bolts feature precision-cut threads that ensure a perfect fit with the stem holes. The precise threading design allows for smooth installation and provides a reliable fastening effect. INSTALLATION TOOL: These bolts are installed using an Allen wrench, also known as an internal hex tool. The Allen wrench is a common bicycle maintenance tool that allows for easy tightening and loosening of these bolts, making the installation process convenient and efficient. other.