altezzaclio wrote:
鎖緊扭力只剩三十%,...(恕刪)
最近又看到一些資料，可能可以得知使用防卡劑，扭力剩30%是錯誤的：
https://youtu.be/G0YJVk4r_sI?si=eYv_ARaJ3DfesUuW
以潤滑性最好的石墨來說，扭力也才下降到55%，所以使用防卡劑，扭力下降到30%很不合理
https://www.westcoastfasteners.com.au/pdf/ajax%20handbook.pdf
上述參考手冊的49-52頁我截取一些重點：
Because friction is the major unknown variable affecting the relationship between torque applied and tension induced, the presence of light oil lubrication is the minimum standard recommended for consistency in controlled tightening of fasteners. Most plain finish fasteners are supplied with a sufficient oil residue from their processing but plated finishes will generally require oiling or adjustment to the torque recommended in Ajax Fasteners’ Technical Data.
In recent tests of bright zinc plated parts the tension at a given torque was found to progressively reduce by 50% over five tightenings of an unlubricated assembly while a well lubricated assembly showed no reduction over five retightenings and only a 9% over twelve retightenings. The results of these tests are shown in Figures 15-18.
https://youtu.be/-0qCn1IUv5o?si=m55M5QqjDjpZNAtC
（影片後段提到這個參考手冊的內容）
因為Google 翻譯還是不太正確，我簡單的說，就是螺絲仍是需要有少量的潤滑油，原廠規範的螺絲要Dry, 不能有油脂，是指不能用丙酮類的去油脂劑去清潔螺絲，同時我在取得BBS 原廠鋁圈螺絲時，包裝打開我發現每一顆都有油，而且是佈滿整顆螺絲，只是這種油不像機油這麼黏稠
手冊與影片提到的：要使螺絲在固定扭力下提供穩定的夾緊力道，需要有輕微的潤滑
沒有輕微潤滑，多次鎖緊，夾緊力道的變化：
有潤滑：
可以看到有潤滑的穩定很多.
而我在做原本原廠建議的130Nm鎖緊扭力時，是用去油脂很強的洗劑去洗，洗到完全乾澀，因此鎖到130Nm時的夾緊力，應該低於BBS 新螺絲含油的狀態，以至於我量測上發卡劑後的扭力也偏低，從目前文獻來看，上防卡劑，SAE 40號的油，扭力需要下降40-55%就很多，下降到30%太誇張了
