i recently purchased a 4 inch screw for my DIY project and I`m glad I chose this PRODUCT .According to my experience, this industrial and scientific screw is strong and durable, making it ideal for heavy-duty applications. The screw has a deep thread that provides excellent grip and prevents slipping. The only con is that it's a bit pricey compared to other screws available in the market. overall I highly recommend this screw for anyone looking for a reliable and sturdy fastener..