An alarmed federal government took steps yesterday to protect U.S. industry from another major competitive threat from abroad:

Imported nuts, bolts and screws.

The International Trade Commission asked President Carter to raise the duties on these objects - which could raise the prices paid by weekend carpenters in hardware stores across the nation.

On a 3-to-1 vote, the ITC decided to recommend the higher tariff, which would affect mainly Japanese and Taiwanese manufacturers who sell hundreds of millions of dollars worth of nuts, bolts and screws in this country.

Carter has 60 days in which to accept the recommendation or come up with his own approach. Congress then has three months to accept or reject his decision.

The ITC acted after it learned that foreign screws, bolts and nuts are penetrating the U.S. market at an alarming rate - taking a growing share of sales and cutting employment in U.S. plants.

Sales of these imports will exceed more than $300 million this year, the commission found, but the products carry almost no import tax. A 10 per cent duty is levied on large screws.

The recommendation came on the heels of an administration plan, disclosed this week, to put a floor under the price of imported steel to help domestic producers become more competitive.