The Flight Attendants Union Coalition, representing 90,000 flight attendants nationwide, called the decision outrageous and shortsighted, and asked Pistole to reconsider.
"We believe that these proposed changes will further endanger the lives of all flight attendants and the passengers we work so hard to keep safe and secure," the group said.
The TSA said on its website, "The decision to permit certain items in carry-on bags was made as part of TSA's overall risk-based security approach and aligns TSA with International Civil Aviation Organization Standards and our European counterparts."
"It's an intelligence-based, risk-based decision," said TSA spokeswoman Ann Davis. "It's part of his [Pistole's] overall risk-based approach to security."
Airlines for America, the trade group representing U.S. airlines, favored the move. "We support TSA's approach of combining its vast experience with billions of passenger screenings with thorough risk-based assessments," it said in a statement.
Flight attendants weren't buying it. "While we agree that a passenger wielding a small knife or swinging a golf club or hockey stick poses less of a threat to the pilot locked in the cockpit, these are real threats to passengers and flight attendants in the passenger cabin," said Stacy Martin, president of Southwest Airlines' flight attendants.
Still banned in passenger cabins are knives with locking or fixed blades and molded grips, and razor blades and box cutters.
The agency will allow souvenir novelty baseball bats less than 24 inches long and will permit lightweight plastic bats even if they are more than two feet long that are sporting equipment.
Besides aligning with international standards, the TSA concluded that small pen knives are not going to cause catastrophic damage to aircraft. Passengers routinely carry things that could injure others - a pen, knitting needles, the heel of a shoe.
The greatest threat to air travelers is explosive devices, not a Swiss Army knife or sporting equipment, said TSA spokesman David Castelveter.
By not having to search for and remove these items, security screeners "can spend more time looking for explosive devices" - and work to improve the passenger experience, he said.
American Airlines' 16,000 flight attendants' union said it welcomed periodic review of banned items on airplanes, but said knives of any kind should not be allowed in the cabin.
Relaxing restrictions on hockey sticks, golf clubs, and ski poles "could lead to a more stressful and potentially dangerous environment for air travelers and employees," the group said.
Contact Linda Loyd at 215-854-2831 or lloyd@phillynews.com.