Baseball Reference has a free trial for their Play Index, so I’m giving it a whirl.
Who are the worst hitting pitchers of all time? I’ve got no magic criteria, but it’s easy find some guys who were epic fails at the plate.
Rob Herbel pitched in 332 games in the 60s and early 70s, mostly for the Giants. He managed only six hits in 227 plate appearances for an anemic .029 batting average. He struck out 125 times (55% of PAs) and walked only eight times. Actually, one third of his hits were doubles, which raised his OPS to .104. I bet a few of those doubles were hit to sleeping outfielders.
Dean Chance won the AL Cy Young in 1964 and accumulated 759 plate appearances in 406 games. He recorded 44 hits, all but two of which were singles. He struck out 420 times (55%) and walked only 30 times. With 128 wins and a 2.92 career ERA, he’s probably the best pitcher ever who was useless with a bat in his hands.
Of the active guys, Tommy Hanson & Ben Sheets are notable. Hanson is 11 for 187 (.059) with 92 strikeouts, 5 walks, and zero extra-base hits. Sheets is 34 for 449 (.076) with 212 Ks and 19 walks.

Although Randy Tate was in the bigs for only one year, he holds the distinction of having the most career plate appearances (47) without a hit. He did manage to draw one walk, though! In six minor league seasons he hit .113, so I guess ’75 was just a down year for him. Tate had an unusually symmetric career: three years in the minors, followed by one full season with the Mets (He pitched in every month of the ’75 season.), followed by three more years in the minors. He was never called up during his minor league seasons, and wasn’t sent down during his only major league season!
And, finally, of the pitchers with the dubious distinction of never having reached base safely ever, the guy with the most plate appearances (33) is none other than Justin Verlander. I think I’ve heard that he’s a decent pitcher, though. Verlander did not reach base during his three post-season PAs, and he never went to the plate during his 20-game minor league career. Let’s hope that the increase in interleague play will give Justin the chance to get off the schneid in 2013.