Product Description
OZ-Post® T6-850 Wood Post Anchor — 6″×6″ (Fits 5-1/2″×5-1/2″) — 36″ Length
- Fits 6 x 6 (5-1/2" Actual) Square Wood Posts
- Perfect for Arbors, Pergolas, Swing Sets, & Other Outdoor Projects that Require 6 x 6 Posts
- Approved for Use with ACQ Treated Wood Posts
- Easy Install - Drives Into the Ground in Minutes Using a Jackhammer
- Can Be Installed Using Manual Techniques for Small Projects
- Installs in Asphalt & Other Hard Surfaces
- Extend the Life of Your Wood Posts - Prevents Rot & Insect Damage that Happens Below Ground
- Hot-Dip Galvanized for Long Lasting Performance in Any Climate
OZ-Post T6-850 Wood Post Anchors are designed for treated 6 x 6 Posts, which are actually 5-1/2" x 5-1/2". These large anchors work great for fences, pergolas, arbors, and other outdoor projects that use 6 x 6 posts. If your project requires load bearing capacity or will be particularly top heavy, we recommend using the T6-700 which is designed to work with the OZ-Deck load bearing plates.
Oz-Post Wood Anchors not only secure posts in the ground, but they also protect them from rot, mildew, and insects by keeping them out of the moist ground. The hot-dip-galvanized sleeve limits ground contact.
You can drive these anchors flush with the ground and secure your posts with a strong adhesive, or you can leave the sleeve above ground and use wood screws to secure the post. The added benefit of leaving the sleeve above ground is that it will protect your post from damage by common yard maintenance tools like weed eaters and lawn mowers.
T6-850 anchors can actually be driven into the ground in 3 ways:
- Insert a spare piece of 6x6 into the OZ-Post sleeve so that it sits 5-6" above the sleeve height. Use a sledge hammer to pound down on the wood, driving the anchor in the ground. This technique is good installing a small number of OZ-Posts in a reasonable amount of time.
- Use the Manual Driving Kit plus an HSP-T6 spacer, which uses weight and gravity, to drive the T6-850 OZ-Posts into the ground.
- Use the Jackhammer Driver Kit (JDK) and a HSP-T6 Spacer, along with a rented jackhammer to drive in as many OZ-Posts as you need. This is the quickest and least labor intense way, but may not be as cost effective for small projects (1-6 posts)
Why Choose This
- Cleaner jobsites — No digging, no concrete, minimal mess
- Drive-and-build workflow — Set posts and start framing the same day
- Long-term durability — Thick zinc coating resists corrosion; ACQ-compatible
Specifications
| Model | T6-850 (6×6 Wood Post Anchor) |
| Fits Post Size | 6″×6″ nominal (actual 5-1/2″×5-1/2″) wood posts |
| Anchor Length | 36″ overall |
| Top Sleeve Length | Approx. 6″ sleeve (square) |
| Material / Finish | 3 mm hot-dip galvanized steel; ACQ-compatible |
| Driver Options | Manual Driver Kit (MDK-13) or Jackhammer Driver Kit (JDK-10) |
| Included | T6-850 anchor (post fasteners not included) |
| Typical Usage | Pergolas, arbors, privacy fences, signage, landscape structures |
Installation
Lay out post locations and call 811 to locate utilities. Using a manual driver or jackhammer driver kit, drive the T6-850 to grade while checking plumb. Insert the 6×6 post and fasten through the sleeve with exterior-grade screws or bolts. If any sleeve holes land below grade, seal with polyurethane adhesive/sealant to reduce moisture intrusion. Rocky or bedrock conditions may require pre-drilling or an alternate footing.
Resources: Installation Instructions (PDF) | Manufacturer’s Warranty
Buying Guide
- Soil & load: Choose T6-850 for deeper embedment on taller/heavier runs. If the project is particularly top-heavy or requires a bearing plate system, consider models designed to pair with OZ-Deck plates.
- Fasteners: Secure posts with exterior-grade hardware—see our bolts & fasteners and galvanized carriage bolts.
- Tools: Small jobs are manageable with a manual driver; larger runs go faster with a jackhammer driver kit.
Frequently Asked Questions
- Do I need to pour concrete?
- No. T6-850 is a drive-in anchor designed to eliminate digging and concrete in qualifying applications.
- Is it compatible with pressure-treated lumber?
- Yes. The galvanized construction is suitable for ACQ-treated wood.
- How deep is the anchor?
- It is 36″ long overall with an approximately 6″ top sleeve.
- Which tools do I need?
- Use a manual driver kit for small runs or a jackhammer driver kit for faster installation.
- Can it be used in asphalt or rocky ground?
- It can be driven through asphalt and will often deflect around small rocks; solid bedrock typically requires pre-drilling or a different foundation.
Comparison
| Option | Strengths | Considerations | Best For |
|---|---|---|---|
| T6-850 (36″) (this item) | Deeper embedment for taller posts/heavier runs | More driving effort than shorter models | Pergolas, arbors, privacy fences, signage |
| T4-850 (34″) | For 4×4 posts; similar deeper embedment | Smaller post size | Standard 4×4 fence lines |
| Traditional Concrete Set | Customizable footing; familiar method | Digging, cleanup, cure time | Sites where code/soil requires footings |
Not sure if a 36″ anchor is right for your soil and post height? Contact us and we’ll help you select the right OZ-Post model and hardware for a durable, clean install.
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Product Reviews
3 Reviews Hide Reviews Show Reviews
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T6-850 Oz-Post Anchors
I ordered 6 of these anchors, a set of 4 and another 2. They're great products. I highly recommend a jackhammer with the Ozco driving kit to drive them. The 2 individual ones came nicely boxed in 2 individual boxes. The set of 4 came in an inadequate box that was torn up, with Oz-posts bursting out of the box. The posts are pretty indestructible, so it wasn't a big deal, but the packaging on the set was definitely poor. The shipping charge was pretty expensive, so I'd expect a bit more care in the packaging.
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Oz-Post T6-850 Review
I bought these anchors for an arbor. I did not want to dig holes and pour concrete around the wood post because the holes for a 6x6 post post would need to be large and deep to get below the frost line here in Iowa. These post were easier to install and the post will not rot form the ground contact. They are a great product and purchasing them from Signet Fence was a fast and easy. They sold me the number of anchor I needed and shipped them fast.
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Oz-Post T6-850 - Post Anchor
Very satisfied with purchase, but had to wait two months for my order to arrive due to suppliers lack of inventory.
