There is no way I would be in this business without a good CPA. The FET for fishing tackle falls under the Sport Fishing Tax. As mentioned before all manufactured fishing tackle is subject to this 10% tax. To the IRS it does not matter how large or how small of sales you make. To them if you sell a product you are fair game. For the best information contact your IRS office and they can help you obtain your FET number and/or provide you the book better describing this tax. This tax must be paid every quarter.
You can just about be guaranteed to be audited for this so keep very good records. When they audit you they will ask to see every sale, every purchase and they want to know how many pieces you have in stock. When audited your purchases, sales and inventory all need to balance. FET is not subject to deductions. If you make a sale they get 10% period. This is not a tax to play with at all.
Some companies you sell to will also require you to carry a $1.5 million dollar liability insurance policy or they will not carry your products. Check with your insurance company for this.
Welcome to the tackle industry. Making product is easy. Making money at it is another thing.