HULK Metal has been engaged in the production and sales of Spherical Head Lifting Anchor for more than 20 years. In this article, we mainly introduce its materials, production, quality inspection, some uses, and how to choose a more suitable supplier. Through this article, you can understand it more fully.

Spherical Head Lifting Anchor：

The origin of this name: 

it requires the use of a spherical head lifting clutch to complete the lifting of the concrete slab, and a spherical recess former is required to leave a spherical groove on the concrete precast slab.

It has several other names:

Dog bone lifting anchor: because its overall shape resembles a dog's molar bone.

Lifting pin anchor: is the most direct name.

Material:

It needs to be produced with high-strength alloy steel bars, and common materials include 20Mn2, Q345, CM490. Of course, stainless steel is also used in some prefabricated concrete structures that need to be frequently dismantled and installed. Before production, the raw materials need to pass a certain tensile coefficient test.

Production: 

It is usually produced by hot die forging. The brief steps are: cut the steel bar into a specific length, heat the steel bar, put the heated steel bar into the die, close the die, get the spherical head lifting anchor with flash, cut off the flash after cooling, and get the raw black finished product.

Surface Treatment:

Common surface treatments include electrogalvanizing and hot-dip galvanizing. Many customers also purchase raw black, which means no surface treatment. In this case, we will apply a layer of anti-rust oil to it and do a good job of rust prevention during transportation.

Electro galvanizing: 

has a brighter surface, better appearance, and the coating is more uniform than hot-dip galvanizing, but the coating is thinner.

Hot-dip galvanizing:

has a whiter surface, relatively poor appearance, and the coating is not very uniform. But it is thicker overall.

Cost:

When there is no requirement for coating thickness, the cost of hot-dip galvanizing is higher. As for the reason: hot-dip galvanizing requires a long time to maintain the molten state of zinc.

Quality Control:

Quality inspection process includes the following:

Sampling inspection of raw materials: testing the tensile properties of raw materials. This process often requires more than 3 times the load capacity of the spherical head lifting anchor. For example: a spherical head lifting anchor with a SWL of 1.3 tons needs to be tested with more than 3 times the tensile force, that is, at least 3.9 tons. The finished product also needs to be strictly sampled using this standard. In addition, we will also conduct periodic breaking tests to test its ultimate tensile strength.

We will attach a detailed test report to each batch of goods.

Use:

Its use can be divided into two links, one is the installation link, and the other is the lifting link:

Installation:

Its installation requires a recess former, you can refer to the picture below.

The recess former has three materials: plastic, rubber, and magnetic.

It can be installed on the horizontal and vertical surfaces of the precast concrete structure. There are several installation methods for the two installation methods:

For specific installation parameters, it is recommended that you consult a professional project company because we can only provide you with professional technical support on the product side.

The use of three anchors ensures that the static load is shared evenly.

If the anchors cannot be placed symmetrically to the center of gravity, the load on the anchors must be calculated according to simple static design rules.

Unequal loads on the anchors resulting from anchors positioned asymmetrically to the center of gravity:

The load always is searching for its position with the center of gravity under the hook.

If a lifting sling is used in a triangle form, the acting forces on the anchors (sling loads) are increased compared to simple vertical lifting. As the angle of lift (β) increases, the acting forces on the anchors and slings increase as well. This influence is taken into account by factor ω dependent on angle β.

For a beam with more than two suspension points and a panel with more than three, it is impossible to precisely work out the load per anchor, even if the anchors are arranged symmetrically to the load center. Due to unavoidable tolerances in the suspension system and the position of the anchors, it can never be determined whether the load on each anchor is equal.

The use of tolerance-compensating suspension systems (e.g. articulated lifting beam combinations, multiple slings with compensating rig, etc.) permits exact load distribution, but should only be used by experienced specialists, also bear in mind that such a system must be used both in the yard and on-site. In case of doubt, only two anchors should be assumed to be load-bearing.

Two anchors are recommended for beams and upright panels, and four anchors installed symmetrically to the load center are recommended for horizontal slabs. In both instances, two anchors will be bearing equal loads.

The use of three anchors ensures that the static load is shared evenly.  

Number of loadbearing anchors: n = 3

Only two anchors can be assumed to be load-bearing for an arrangement of four independent cable runs or continuous diagonal cable runs.

Number of Spherical Head Lifting Anchors: n = 2

A perfect static weight distribution can be obtained by the use of a spreader beam and two pairs of anchors set out symmetrically.

Number of Spherical Head Lifting Anchors: n = 4

The system with a compensating rig makes it possible to distribute the load evenly over 4 anchors.

Number of Spherical Head Lifting Anchors: n = 4

A perfect static weight distribution can be obtained using a crossed spreader beam, which avoids angled pull.

Number of Spherical Head Lifting Anchors: n = 4

Lifting:

Its lifting needs to be completed by a dedicated spherical head clutch. For specific content, please refer to the article on Lifting Clutch:

Application:

It can be installed in prefabricated concrete parts such as culverts, prefabricated houses, stairs, etc. to provide connection points for their hoisting.

Choose a Suitable Supplier:

A suitable supplier does not mean that he needs to be excellent or even the top in the industry, as long as he can meet your requirements and continue to provide high-quality services in your future development.

Technical Support:

Companies with technical teams can make reasonable technical suggestions based on your needs and develop perfect solutions when you have customized needs. For mature products such as spherical head lifting anchor, there may not be special requirements. When you need to purchase some special similar products, you can also ask your suppliers (if they have a technical team), and they will develop a more reasonable solution for you.

Supply Capacity:

Some suppliers will meet your purchasing needs at this stage. But as you continue to progress, you need to purchase more other types of products. At this time, the role of a suitable supplier is to develop with you, meet your needs, and continue to surprise you.

For example: At this stage, you only purchase spherical head lifting anchors with SWL between 1.3 Ton - 10ton. They can meet your requirements. When you purchase products from other units, they can also meet your requirements. And other products such as lifting clutch, recess former, or lifting sockets can be provided. At this time, they will become your solid backing.

Production Capacity:

We have summarized the current types of suppliers: those with inventory and those without inventory.

Suppliers with Inventory:

It is reflected in his inventory capacity. They often have a large inventory to deal with your urgent and large-volume order purchases. This kind of supplier will incur certain costs such as storage costs, capital costs, etc. And these costs will be included in the unit price of the spherical head lifting anchor, which will lead to price increases. Therefore, it is more appropriate to choose a supplier with inventory when your needs are urgent.

Suppliers without Inventory:

It is reflected in their production capacity and factory management capabilities. They often have abundant factory resources to deal with the production scheduling after receiving orders. Through this flat management, the production of multiple orders can be started at the same time. Even if there is no inventory, a certain amount of goods can be delivered in a shorter time. Because there is no restriction on capital retention costs, storage costs, and time costs, the unit price of a spherical head lifting anchor is lower. Therefore, it is more appropriate to choose a supplier with no inventory and factory resources for orders that are not urgent.

Service Capabilities:

It can be mainly divided into service items and service quality for comprehensive consideration.

Service Items:

Reflected in the ability to integrate the supply chain. A supplier with a complete supply chain can not only handle products but also provide packaging, transportation and other services you may need to help you save more time and energy.

Service Quality:

reflected in the comfort level of customers. For example, when we serve customers, customers only need to make requests and we will try our best to meet them. Helping customers save time is also our priority. They do not need to go to the factory again and again to check the production progress in person, but will receive implementation reports from us in various ways.

Choosing a supplier with strong service capabilities can save you more time and energy and handle multiple orders at the same time.

Strong service capabilities do not mean that costs will increase a lot because improved efficiency often means more savings.

We are an experienced and responsible supplier. We are very eager to serve you, but we hope you can find a more suitable supplier. Of course, before that, you can contact us to get a quote and experience our services for comparison.