The lowest cut line in the history of the PGA Tour is 136, which is 4 under par, set in the 2011 Travelers Championship. However, the lowest 36-hole cut against par is 6-under total, set six different times in PGA Tour history -- most recently at the 2008 Shriners Hospitals for Children Open.
The lowest cut line in LPGA Tour history was set at the 2017 Bank of Hope Founders Cup, with the 36-hole cut coming at 5-under 139. The winning score for the tournament was 25 under par, won by Anna Nordqivst, who came up two shots shy of tying the 72-hole LPGA scoring mark against par, set in the 2016 version of the event and by Annika Sorenstam in the 2001 Standard Register Ping. All of those tournaments were held in Arizona.
The lowest 36-hole cut in Masters history is 1-over 145 in 2011, as well 1979, 1992, 1995, 2001 and 2009. Before 1957, the Masters did not have a cut.
The lowest 36-hole cut in Open Championship history is 143, most recently matched in 2011 at Royal St. George's.
The lowest 36-hole cut in PGA Championship history is 1-over-par 141, set in the 2001 PGA Championship at Atlanta Athletic Club in Georgia. Prior to 1958, the PGA Championship was a match play event and had no cut.