斯里兰卡采购需求：螺栓、螺母、螺钉、垫圈、锚栓、螺纹杆

I'm interested in purchasing black bolts and nuts with a specified grade. I'd like to know about your product availability, including different sizes and any minimum order quantities you might have. Additionally, please provide me with pricing details and lead times for the delivery. If there are any specifications or certifications that your products meet, I'd appreciate it if you could share that information as well. Thanks!