When you look at the picture attached to this email can someone tell me what the purpose of the channel machined lengthwise in the threads on the block end of this head stud?<div id="yMail_cursorElementTracker_1587345442276">Mike MacLean<br><div class="yahoo-compose-assist-image-card ymail-android-inline-img-container ymail-card" contenteditable="false"><img id="ymail_attachmentId26766" class="inline-image-global inlined-image-cid-6a44c9a8-89c3-41fa-8aa9-361198f22f57" src="cid:6a44c9a8-89c3-41fa-8aa9-361198f22f57" style="width:100%;max-width:800px;"><br></div><br><br><br><div id="ymail_android_signature"><a id="ymail_android_signature_link" href="https://go.onelink.me/107872968?pid=InProduct&c=Global_Internal_YGrowth_AndroidEmailSig__AndroidUsers&af_wl=ym&af_sub1=Internal&af_sub2=Global_YGrowth&af_sub3=EmailSignature">Sent from AT&T Yahoo Mail on Android</a></div></div>