The step on the boss has to be lower than the thickness of the blade carrier or have a stepped washer so that the blade carrier is sandwiched up tight when the bolt/nut is tightened. The clamping force is what has to hold the carrier tight

Entire Thread
Subject	Posted By	Posted
Rockwell - Slightly Broken Mower Disc. Fixing?	Widget	25/12/16 05:31 PM
Re: Rockwell - Slightly Broken Mower Disc. Fixing?	NormK	25/12/16 05:53 PM
Re: Rockwell - Slightly Broken Mower Disc. Fixing?	Widget	25/12/16 09:03 PM
Re: Rockwell - Slightly Broken Mower Disc. Fixing?	NormK	25/12/16 09:13 PM
Re: Rockwell - Slightly Broken Mower Disc. Fixing?	Mowerfreak	25/12/16 10:56 PM
Re: Rockwell - Slightly Broken Mower Disc. Fixing?	NormK	26/12/16 05:24 AM
Re: Rockwell - Slightly Broken Mower Disc. Fixing?	Widget	26/12/16 12:30 PM
Re: Rockwell - Slightly Broken Mower Disc. Fixing?	NormK	26/12/16 01:42 PM
Re: Rockwell - Slightly Broken Mower Disc. Fixing?	bigted	26/12/16 10:58 PM
Re: Rockwell - Slightly Broken Mower Disc. Fixing?	Widget	27/12/16 03:06 AM
Re: Rockwell - Slightly Broken Mower Disc. Fixing?	NormK	27/12/16 04:12 AM
Re: Rockwell - Slightly Broken Mower Disc. Fixing?	aussietrev	27/12/16 07:25 AM
Re: Rockwell - Slightly Broken Mower Disc. Fixing?	Widget	27/12/16 12:13 PM
Re: Rockwell - Slightly Broken Mower Disc. Fixing?	CyberJack	27/12/16 12:22 PM
Re: Rockwell - Slightly Broken Mower Disc. Fixing?	Widget	27/12/16 12:36 PM
Re: Rockwell - Slightly Broken Mower Disc. Fixing?	CyberJack	27/12/16 12:42 PM
Re: Rockwell - Slightly Broken Mower Disc. Fixing?	Widget	27/12/16 12:50 PM
Re: Rockwell - Slightly Broken Mower Disc. Fixing?	CyberJack	27/12/16 01:03 PM
Re: Rockwell - Slightly Broken Mower Disc. Fixing?	Widget	27/12/16 02:06 PM
Re: Rockwell - Slightly Broken Mower Disc. Fixing?	CyberJack	27/12/16 02:21 PM
Re: Rockwell - Slightly Broken Mower Disc. Fixing?	aussietrev	27/12/16 02:59 PM
Re: Rockwell - Slightly Broken Mower Disc. Fixing?	Widget	28/12/16 06:50 PM