When sourcing Australian mortice lock spare parts for a TKAU6400 installation, identify which assembly needs replacement before requesting a price. A lock case, lever furniture and a complete set are different purchasing scopes. Record the parts that will remain on the door so the replacement can be checked against them.
For distributors managing maintenance orders, a useful starting detail is the TKAU6400 interface: the specified follower opening is 7.8 mm and the spindle is 7.6 mm. These are different dimensions. Calling both “8 mm” removes information needed to compare a replacement with the existing hardware.
Choose the replacement scope
The TOPTEK Australian mortice lock range includes TKAU6400EC escutcheon furniture and TKAU6400RR round rose furniture. Establish the installed configuration, then have a qualified installer identify whether the fault is in the case, furniture, cylinder or door alignment.
| Requested scope | What the enquiry must identify | Reason |
|---|---|---|
| Lock case replacement | Existing furniture, spindle, cylinder, strike, function and door preparation | The new case must work with the retained parts. |
| Lever furniture replacement | Installed case, spindle dimensions, fixing positions and existing door holes | Appearance alone cannot establish operating fit or fixing compatibility. |
| Complete set replacement | Required case, furniture, cylinder, strike and fixing contents | A defined set avoids different assumptions about what the quotation includes. |
Confirm the available supply scope and itemised contents on the quotation. A product shown as a complete assembly does not mean every internal component is separately stocked or supplied as a spare.
Keep the two spindle interface dimensions distinct
The TKAU6400EC and TKAU6400RR specifications identify a 7.8 mm follower opening with a 7.6 mm spindle. The follower is the opening in the lock that receives the spindle; the spindle connects the lever operation to the case. Write both values into the enquiry rather than rounding them to a nominal size.
The specified backset options are 60, 89 and 127 mm. Matching the backset helps position the operating parts, but it does not establish complete interchangeability. The function, cylinder interface, furniture fixings, case dimensions and strike alignment must also suit the retained assembly.
For an existing TKAU6400EC installation, send the model identification with photographs of both door faces and the door edge. Include a dimensioned sketch of the preparation if the original order record is unavailable. Do not identify another manufacturer’s case as interchangeable solely because the furniture looks similar.
Let the diagnosis determine the purchase
A lever that does not return correctly is a symptom, not a spare-part number. The installer should establish whether the problem follows the furniture, its mounting, the spindle engagement or the lock case. If the latch fails to withdraw, the latch retraction guide can help organise the information sent with the service enquiry.
Replacing only the affected assembly can retain suitable existing hardware, provided the remaining components are identified and compatible. A complete set may be appropriate when several interfaces are unknown or the project is changing the function. That choice should follow the installation findings and the proposed set contents.
Make repeat orders traceable to the installed set
As a commercial door hardware manufacturer, TOPTEK supplies product configurations that buyers can reference by model and agreed order details. Retain the accepted quotation and sample configuration with the door reference, finish, handing and keying details. Include the inspection requirements agreed for the order alongside TOPTEK’s quality management information.
This record lets a later maintenance enquiry identify what was actually supplied. It also helps separate a like-for-like replacement from a change that needs a fresh compatibility review.
Request the replacement contents you need
Send TOPTEK your TKAU6400 replacement enquiry with the existing model, installer findings, photographs, measured interfaces, quantities and a list of retained parts. State whether you want a case, furniture or a complete set quotation, and ask for the included components to be itemised.
Frequently Asked Questions
Are the TKAU6400 follower and spindle both 7.8 mm?
No. The specified follower opening is 7.8 mm and the spindle is 7.6 mm. Record both dimensions when checking replacement parts.
Does a matching backset prove that a replacement case will fit?
No. Check the function, spindle, cylinder interface, case dimensions, furniture fixings and strike alignment as well as the backset.
Can every TKAU6400 component be ordered separately?
Separate-component availability must be confirmed for the requested item. Ask the quotation to identify exactly which parts are included.