I recently pulled a small screw from one of my tires, which is quite new. It had penetrated to a depth of about 1/2 an inch. The tire is not losing pressure. My question is this: although the tire was not fully penetrated, will the damage have created a weakness that could, perhaps at high speed on a hot day, cause a blow-out?
That depends, was the screw in the sidewall or very close to it, or was it in tread area? If in the sidewall, then you might have a problem. If in the tread area, then the worse case is that a leak may develop later, but not a blow out.
If it holds air, I’d say its ok. If you ever have a problem balancing the tire, then you’d have some cause for concern. If the belt was damaged it would eventually start to separate and there are usually symptoms, out of round, slight tracking from side to side that let you know a belt is going bad. I’d say a sudden blow out is low risk. If it were my tire I’d drive on.
If you want to be perfectly safe, get a new tire. My answer assumes the screw was in the tread area of the tire. Sidewalls are made to flex and if the screw is from the sidewall of the tire you could need a new one.
If the puncture reaches the steel belts in the tire, moisture can get to the steel belts causing them to corrode. This won’t present itself as a problem right away, but could show up as a tire failure later on down the road.
I agree with Tester. It is probably not possible for the OP to know whether the puncture went as far as the steel belts, but that possibility would cause me to err on the side of caution and replace the tire. I would not put this into the “emergency–replace immediately” category, but replacement of that tire should be on the agenda for the OP in the near future before rust has a chance to start weakening the steel belt.
Many years ago, I worked in a Citgo service station at one of the rest stops of the NJ Turnpike. Naturally, the cars of the NJ state troopers were maintained at the central NJSP garage, but tire problems were dealt with at the rest stop service stations simply because of the time factor involved in towing police cars for a very long distance to get to the NJSP garage.
The cardinal rule was–in the event of a puncture, no matter how minor–replace the tire! And, you should bear in mind that these were extremely expensive tires, namely Goodyear Blue Streak racing tires with a “safety spare” contained inside the tire. Each service station on the turnpike kept a stock of these Goodyear Blue Steaks handy, in case they were needed by the state police.
The cost of replacing those tires as a result of one tiny puncture was very high, but when your life is riding on your tires (as Michelin implies in their advertising), it pays to err on the side of caution and spend the money on a new tire. It should also be noted that this was in the days before radial tires, so there was no steel belt that might rust. The possibility that the tire’s integrity had been compromised in any way was enough for the State of NJ to spend the money for a new tire.
On a side note, those state trooper cars were really quite something. Imagine a HUGE Chrysler New Yorker Six Window Sedan (circa 1968-69) equipped with the special police pursuit package, including the 440 c.i. V-8 modified for higher output than normal. I drove one of those cars only once (across the parking lot of the station) and to say that the acceleration was “awesome” was merely an understatement.