Soil nailing is a **passive** stabilization technique for slopes and excavation faces, where the ground is "reinforced" by installing steel bars (nails) into drilled holes and then grouting them with cementitious grout, often combined at the surface with a facing (shotcrete/sprayed concrete with mesh and head plates). It is defined as passive because the nails are not prestressed: they become engaged as the ground tends to deform, mobilizing the bar–grout–ground bond and creating a reinforced mass that improves resistance to sliding/overturning and limits deformations. Installation is typically carried out top-down, in stages, as excavation or works progress.

### Fully threaded bars
Fully threaded bars are used as rock bolts or soil nails, installed in predrilled holes and fixed with resin cartridges or cement grout. Continuous threading allows nuts and couplers to be placed at any position, facilitating joints, adjustments, and the installation of bearing plates and prestressing hardware.

### Self-drilling hollow bars
Self-drilling hollow bars (SDA) act both as the drilling rod and as the load-bearing element. Drilling and grouting can be carried out simultaneously through the central bore, reducing the risk of hole collapse in loose soils, debris covers, or highly fractured rock, and improving productivity in challenging conditions.

**In accordance with Ministerial Decree (D.M.) No. 8 of 17/01/2018 "Technical Standards for Construction"**

<table>
  <thead>
    <tr>
      <th>B450C</th>
      <th>CODE</th>
      <th>LR20B</th>
      <th>LR25B</th>
      <th>LR28B</th>
      <th>LR32B</th>
      <th>LR40B</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>Nominal diameter</td>
      <td>mm</td>
      <td>20</td>
      <td>25</td>
      <td>28</td>
      <td>32</td>
      <td>40</td>
    </tr>
    <tr>
      <td>Grade</td>
      <td>N/mm²</td>
      <td colspan="5">450/540</td>
    </tr>
    <tr>
      <td>Minimum yield load</td>
      <td>kN</td>
      <td>141</td>
      <td>221</td>
      <td>277</td>
      <td>361</td>
      <td>565</td>
    </tr>
    <tr>
      <td>Minimum ultimate load</td>
      <td>kN</td>
      <td>169</td>
      <td>265</td>
      <td>332</td>
      <td>434</td>
      <td>678</td>
    </tr>
    <tr>
      <td>Agt</td>
      <td>%</td>
      <td colspan="5">≥ 7.5%</td>
    </tr>
    <tr>
      <td>Average area</td>
      <td>mm²</td>
      <td>314</td>
      <td>490</td>
      <td>615</td>
      <td>803</td>
      <td>1255</td>
    </tr>
    <tr>
      <td>Weight</td>
      <td>kg/m</td>
      <td>2.47</td>
      <td>3.85</td>
      <td>4.83</td>
      <td>6.31</td>
      <td>9.86</td>
    </tr>
    <tr>
      <td>Min./max. diameter</td>
      <td>mm</td>
      <td>20/23</td>
      <td>25/29</td>
      <td>28/32</td>
      <td>32/36</td>
      <td>40/45</td>
    </tr>
  </tbody>
</table>

<br>

<table>
  <thead>
    <tr>
      <th>STD</th>
      <th>CODE</th>
      <th>LR20S</th>
      <th>LR25S</th>
      <th>LR28S</th>
      <th>LR32S</th>
      <th>LR40S</th>
      <th>LR50S</th>
      <th>LR57S</th>
      <th>LR63S</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>Nominal diameter</td>
      <td>mm</td>
      <td>20</td>
      <td>25</td>
      <td>28</td>
      <td>32</td>
      <td>40</td>
      <td>50</td>
      <td>57.5</td>
      <td>63.5</td>
    </tr>
    <tr>
      <td>Grade</td>
      <td>N/mm²</td>
      <td colspan="6">500/550</td>
      <td colspan="2">555/700</td>
    </tr>
    <tr>
      <td>Minimum yield load</td>
      <td>kN</td>
      <td>157</td>
      <td>245</td>
      <td>308</td>
      <td>402</td>
      <td>628</td>
      <td>982</td>
      <td>1441</td>
      <td>1758</td>
    </tr>
    <tr>
      <td>Minimum ultimate load</td>
      <td>kN</td>
      <td>169</td>
      <td>265</td>
      <td>332</td>
      <td>434</td>
      <td>678</td>
      <td>1078</td>
      <td>1818</td>
      <td>2217</td>
    </tr>
    <tr>
      <td>Agt</td>
      <td>%</td>
      <td colspan="8">≥ 6%</td>
    </tr>
    <tr>
      <td>Average area</td>
      <td>mm²</td>
      <td>314</td>
      <td>490</td>
      <td>615</td>
      <td>803</td>
      <td>1255</td>
      <td>1963</td>
      <td>2596</td>
      <td>3167</td>
    </tr>
    <tr>
      <td>Weight</td>
      <td>kg/m</td>
      <td>2.47</td>
      <td>3.85</td>
      <td>4.83</td>
      <td>6.31</td>
      <td>9.86</td>
      <td>15.41</td>
      <td>20.38</td>
      <td>24.86</td>
    </tr>
    <tr>
      <td>Min./max. diameter</td>
      <td>mm</td>
      <td>20/23</td>
      <td>25/29</td>
      <td>28/32</td>
      <td>32/36</td>
      <td>40/45</td>
      <td>50/56</td>
      <td>57.5/63</td>
      <td>63.5/70</td>
    </tr>
  </tbody>
</table>

<br>

<table>
  <thead>
    <tr>
      <th>MID</th>
      <th>CODE</th>
      <th>LR20M</th>
      <th>LR25M</th>
      <th>LR28M</th>
      <th>LR32M</th>
      <th>LR40M</th>
      <th>LR50M</th>
      <th>LR57M</th>
      <th>LR63M</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>Nominal diameter</td>
      <td>mm</td>
      <td>20</td>
      <td>25</td>
      <td>28</td>
      <td>32</td>
      <td>40</td>
      <td>50</td>
      <td>57.5</td>
      <td>63.5</td>
    </tr>
    <tr>
      <td>Grade</td>
      <td>N/mm²</td>
      <td colspan="8">670/800</td>
    </tr>
    <tr>
      <td>Minimum yield load</td>
      <td>kN</td>
      <td>210</td>
      <td>328</td>
      <td>412</td>
      <td>538</td>
      <td>841</td>
      <td>1315</td>
      <td>1740</td>
      <td>2078</td>
    </tr>
    <tr>
      <td>Minimum ultimate load</td>
      <td>kN</td>
      <td>251</td>
      <td>392</td>
      <td>492</td>
      <td>643</td>
      <td>1004</td>
      <td>1571</td>
      <td>2078</td>
      <td>2534</td>
    </tr>
    <tr>
      <td>Agt</td>
      <td>%</td>
      <td colspan="8">≥ 5%</td>
    </tr>
    <tr>
      <td>Average area</td>
      <td>mm²</td>
      <td>314</td>
      <td>490</td>
      <td>615</td>
      <td>803</td>
      <td>1255</td>
      <td>1963</td>
      <td>2596</td>
      <td>3167</td>
    </tr>
    <tr>
      <td>Weight</td>
      <td>kg/m</td>
      <td>2.47</td>
      <td>3.85</td>
      <td>4.83</td>
      <td>6.31</td>
      <td>9.86</td>
      <td>15.41</td>
      <td>20.38</td>
      <td>24.86</td>
    </tr>
    <tr>
      <td>Min./max. diameter</td>
      <td>mm</td>
      <td>20/23</td>
      <td>25/29</td>
      <td>28/32</td>
      <td>32/36</td>
      <td>40/45</td>
      <td>50/56</td>
      <td>57.5/63</td>
      <td>63.5/70</td>
    </tr>
  </tbody>
</table>

<br>

<table>
  <thead>
    <tr>
      <th>PLUS+</th>
      <th>CODE</th>
      <th>LR20P</th>
      <th>LR25P</th>
      <th>LR28P</th>
      <th>LR32P</th>
      <th>LR40P</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>Nominal diameter</td>
      <td>mm</td>
      <td>20</td>
      <td>25</td>
      <td>28</td>
      <td>32</td>
      <td>40</td>
    </tr>
    <tr>
      <td>Grade</td>
      <td>N/mm²</td>
      <td colspan="5">900/1100</td>
    </tr>
    <tr>
      <td>Minimum yield load</td>
      <td>kN</td>
      <td>282</td>
      <td>441</td>
      <td>553</td>
      <td>723</td>
      <td>1129</td>
    </tr>
    <tr>
      <td>Minimum ultimate load</td>
      <td>kN</td>
      <td>345</td>
      <td>539</td>
      <td>676</td>
      <td>883</td>
      <td>1380</td>
    </tr>
    <tr>
      <td>Agt</td>
      <td>%</td>
      <td colspan="5">≥ 3.5%</td>
    </tr>
    <tr>
      <td>Average area</td>
      <td>mm²</td>
      <td>314</td>
      <td>490</td>
      <td>615</td>
      <td>803</td>
      <td>1255</td>
    </tr>
    <tr>
      <td>Weight</td>
      <td>kg/m</td>
      <td>2.47</td>
      <td>3.85</td>
      <td>4.83</td>
      <td>6.31</td>
      <td>9.86</td>
    </tr>
    <tr>
      <td>Min./max. diameter</td>
      <td>mm</td>
      <td>20/23</td>
      <td>25/29</td>
      <td>28/32</td>
      <td>32/36</td>
      <td>40/45</td>
    </tr>
  </tbody>
</table>

<br>