Technical guides for industrial buyers: oilfield drilling tools, pipe molds, rolling mill parts and forged components.https://coresteelworks.com/https://coresteelworks.com/en/blog/how-to-buy-api-7-1-drill-collars-from-china/https://coresteelworks.com/en/blog/how-to-buy-api-7-1-drill-collars-from-china/A practical sourcing guide: what API Spec 7-1 covers, how to qualify a Chinese drill collar manufacturer, which documents to demand, and the exact information to put in your RFQ.Sat, 18 Jul 2026 00:00:00 GMThttps://coresteelworks.com/en/blog/hs-codes-oilfield-tools-pipe-molds-rolling-mill-parts/https://coresteelworks.com/en/blog/hs-codes-oilfield-tools-pipe-molds-rolling-mill-parts/The HS classifications buyers actually use: 8431.43 for drill collars and stabilizers, 8480.49 for DI pipe molds, 8455.30/8455.90 for mill rolls and spares, and 8483.10 for forged shafts — with the reasoning behind each.Sat, 18 Jul 2026 00:00:00 GMThttps://coresteelworks.com/en/blog/what-is-a-non-magnetic-drill-collar/https://coresteelworks.com/en/blog/what-is-a-non-magnetic-drill-collar/What a non-magnetic drill collar does in the BHA, why P550 austenitic steel is used, how magnetic permeability is verified, and what to include in an RFQ.Sat, 18 Jul 2026 00:00:00 GMT