HLN Apparel Garment Tools is a set of free online calculators and reference tables provided by Hualingniao, a custom clothing manufacturer in China. It is designed for apparel buyers, designers, and production staff who need quick, factory-based standards during sourcing and manufacturing. The tools require no sign-up and use the same numbers and tolerances the company applies in its own production workflow. The main features include a fabric weight converter for grams per square metre to ounces per square yard, a size chart converter for Chinese garment sizes to US, UK, EU, and Japanese sizes, a downloadable seven-sheet tech pack template in Excel and PDF formats, measurement guides for T-shirts, hoodies, and shirts, and a reference table of six-digit HS codes for common apparel categories with current US duty rates and CBP rulings. A typical workflow might involve converting fabric weights, translating a Chinese size specification into a Western equivalent, and sending a completed tech pack through the site to request a manufacturing quote. The contact form asks for design details, target quantity, and delivery country, and the company responds with fabric options, a sample plan, and a bulk estimate. These tools support early-stage product development and supplier communication rather than replacing professional pattern making or testing.