Section 4: Mailbox Hardware
Introduction
This section presents common information associated with mailbox
hardware. The mailbox standards sheets
(MB-15(1) and MB-14(2))
contain
detailed information about mailbox hardware, DHT numbers, and installation
guidelines.Types of Supports
There are two general types of mailbox supports and specific hardware associated with each type of support:
- Single Mailbox Support:Any of these supports can be used to support a single mailbox.
- Thin-wall Steel Tube:A 2 to 2½ inch diameter thin-wall steel tube. This type of post can be used with a small, medium, or large sized mailbox.
- Wing Channel Post:A 2 pound/ft wing channel post. This type of post can be used with a small or medium sized mailbox.
- Recycle Rubber Post:A rubber post. This type of post is used only for a small size mailbox.
- Double Mailbox Support:This support is used to support two mailboxes on a single support.
- Thin Wall Steel Tube:A 2 to 2½ inch diameter thin wall steel tube.
- Wing Channel Post:A 2 pound/ft wing channel post.
- Multiple Support:Either of these supports can be used for three or more mailboxes.
- Coat Hanger Support:A 2 inch diameter thin-wall steel tube support frame that has a shape similar to an upside down coat hanger. See Figure 9-8.
- Constant Radius Support:A 2 3/8 inch diameter white powder-coated semi-circular pipe with a constant radius. See Figure 9-9.

Figure 9-8. Coat Hangar Multiple Support

Figure 9-9. Constant Radius Multiple Support
Types of Foundations
There are six types of foundations. Table 9-2 lists the foundations and indicates which type of foundation is used with each type of support.
Type of Support | Type of Foundation | |||||
---|---|---|---|---|---|---|
V-Loc | Wedge Anchor | Driven | Concrete | Embedded | Temporary | |
Thin-Wall Steel Tube | Type 1 | Type 2 | No | No | No | No |
Thin-Wall Multiple (coathanger) | Type 1 | No | No | No | No | No |
Wing Channel | No | No | Type 3 | No | No | No |
Powdercoat Steel (constant radius) | No | No | No | Type 4 | No | No |
Recycled Rubber | No | No | No | Type 4 | No | No |
4 x 4 Wood | No | No | No | No | Type 5 | No |
Plastic Drum | No | No | No | No | No | Type 6 |
Figure 9-10 illustrates the orientation of the supports/anchors relative to the direction of traffic. Where a wedge is used, it is installed on the side of the support nearest the direction of traffic.

Figure 9-10. Orientation of Supports/Anchors for Single/Double Mailbox Installations
Mailbox Bracket
The TxDOT universal mailbox bracket provides a single bracket that can be used to mount a small, medium, or large mailbox to a single or multiple support. Figure 9-11 illustrates the basic mailbox bracket. The extensions are used only with a medium or large mailbox. Bolts with a 3/8 inch diameter should be used to provide a tighter fit and prevent the mailbox from rocking. Figures 9-12 to 9-15 illustrate the attachment of the bracket to mailbox supports.

Figure 9-11. Mailbox Bracket (shown upside down)

Figure 9-12. Attaching the Bracket to a Single Support

Figure 9-13. Use of the Adapter Plate for a Double Mailbox Installation

Figure 9-14. Attaching the Bracket to the Multiple Support

Figure 9-15. Bolting the Bracket to a Multiple Support Tube
The following list of tasks provides step-by-step instructions for putting the bracket together:
- Attach extension bracket (if required):
- For a small mailbox, no extension brackets are used.
- For a medium mailbox, an extension bracket is used on one side only.
- For a large mailbox, extension brackets are installed on each side.
- Bolt angle brackets to bottom of mailbox bracket:
- See Figures 9-12 and 9-13 for orientation with a single or double mailbox support.
- See Figures 9-14 and 9-15 for orientation with a multiple support.
- Bolt bracket to mailbox.
- Bolt assembled bracket/mailbox to support.