北美地区采购需求：黑色磷酸盐干壁钉、C型钩头螺钉、盘头开槽螺钉、弹簧螺母、带法兰的六角螺母、M5槽形螺母

I'm reaching out for a quote regarding square head screws. We are particularly interested in various sizes and materials to meet our project requirements. It would be great if you could provide your available options along with pricing details and lead times. Additionally, please let me know about any minimum order quantities or special packaging options you may offer. We're looking to establish a reliable supply chain, so any info on your production capabilities and quality control measures would also be appreciated. Looking forward to your prompt response!