Investing in America's Small Manufacturers Act This bill amends the Small Business Act to authorize the Small Business Administration (SBA) to guarantee 90% of a loan to a small business manufacturing concern. The SBA may not collect a guarantee fee on these loans of more than $350,000. For loans exceeding this amount, the fee shall be 50% of the guarantee fee that the SBA would otherwise collect for the loan. The SBA must provide training to small manufacturers in obtaining SBA assistance, including on the application process and partnering with participating lenders. This bill authorizes the SBA and its partners to establish partnerships to facilitate outreach to small manufacturers with respect to the application process for SBA loan guarantees. A state or local development company's debenture issued to a small manufacturer for an SBA loan guarantee may not exceed 50% of the project's cost, subject to certain exceptions.