4-40 x 7/16" Round Head Slotted Machine Screw Steel Black

MRL0407B is a 4-40 Round Head head Slot drive screw made of Black Zinc Plated Steel, manufactured by Superneer Limited. It has a length of 7/16 inches and is commonly used in electronics, watches, precision instruments, and 3D printers.

The MRL0407B screw features thread size 4-40, length of 7/16 inches, head type Round Head (head diameter 0.193-0.211 inches), drive type Slot (drive size 0.031-0.039" width), and is made of Black Zinc Plated Steel.

The MRL0407B screw is made of Black Zinc Plated Steel. Superneer provides material test reports (MTR) and RoHS compliance certificates for all products. Black Zinc Plated Steel offers excellent corrosion resistance and mechanical strength.

The MRL0407B screw has a 4-40 thread. This is a UNC (Unified National Coarse) thread with 4-40 specification, widely used in North American applications.

MRL0407B Round Head head Slot drive screws are used in electronics assembly, PCB mounting, precision instruments, watches, 3D printers, optical devices, medical equipment, and consumer products where reliable fastening with Round Head head aesthetics is required.

The minimum order quantity (MOQ) for MRL0407B is 10,000 pieces. The unit price is $0.024 USD for MOQ quantity. Larger quantities receive discounted pricing. Contact [email protected] for custom quotes.

The lead time for MRL0407B is 15-25 days for production. Shipping to USA takes 5-15 days via sea freight, with shipping cost starting from $50 USD. Air freight is available for urgent orders. DDP and FOB terms are both available.

The 4-40 thread is approximately equivalent to M2.5 to M3 (approx). When substituting inch screws with metric screws, always verify the actual diameter and pitch compatibility.

The MRL0407B uses a Round Head head type. Round Head head provides a specific head design optimized for its intended application. This head type is selected based on the specific application requirements for load distribution, aesthetics, and accessibility.

To choose the right screw: 1) Determine the required thread size based on the tapped hole or nut; 2) Select the appropriate length based on the material thickness; 3) Choose the head type based on clearance and aesthetics; 4) Select the drive type based on torque requirements; 5) Choose the material based on environmental conditions. For MRL0407B (4-40, 7/16 inches), ensure your application requires this specific size.

MRL0407B uses Black Zinc Plated Steel finish, while alternative variants in the same thread/length specification include MRL0407S (SUS304 Stainless Steel), MRL0407Z (Blue Zinc Plated Steel). The Black Zinc Plated Steel of MRL0407B is specifically selected because it offers a black decorative finish combined with good corrosion resistance, ideal for consumer electronics, automotive interiors, and applications where both appearance and rust prevention matter. This distinction makes MRL0407B the preferred choice when these properties align with your application requirements.